I did read over your posts. You keep saying I should; I read it before I replied the first time. It's an excellent collection of tips/tricks. I'm just not convinced it would be enough. 40 years is a really short time-window.
If you really want my detailed take on it...
Marriage - pretty much the right advice.
Education - I disagree with your advice about not educating your heirs yourself. The AI makes so many stupid choice about what traits to give wards. You also seem to disagree with your advice, so I'm not sure why it's still in there. The #1 priority in education, to my mind, is always educating two people yourself. Heirs and spares get all the good rulership traits. Third sons you might choose to give things like Content, Slothful, Gluttonous... anything to make them less attractive choices for a succession crisis. Or, if your heir is good enough you're confident in the succession anyways, you could give the third son traits tailored towards hopefully filling a role on your council, or just generally good stewardship traits to make them a vassal.
Administration - I never knew you can create vassals by right-clicking holdings. Probably won't be using it (I'd rather invite nobles and look at their stats first), but glad to learn something new. Otherwise, your advice is perfect... if headache-inducing (lots of clicking, lots of micromanagement).
Assassination - Marrying courtiers just to get an assassin in is brilliant. And I'd never even considered it. I will definitely be using this. Otherwise, all good advice.
Pope - I note you don't mention banking invasion CBs. This is one of my preferred tricks for fast early expansion if I can do it - get 1k piety or more, queue up 2-3 invasion CBs while small, then knock them all off in order. If your ruler dies or the target ruler dies before you can finish that invasion CB it's wasted of course... but it can let you get invasions on multiple realms all only slightly larger than you.
Making Gold - Banishment can be an option at times as well - it's a hefty penalty to relations, so it's not something I would do until and unless I was ready to banish all my Count+ vassals. Then you invite new people to your court and hand out all those titles to new rulers. Late-game, I wouldn't do it - you'd have to banish a lot of claimants you were interested in too, and it would be a mess. But early-game... if you get a high starting intrigue, good starting spymaster, and good starting martial, you can imprison-banish your way through a duchy or two fairly readily.
CBs - again, I'm not convinced Holy War would be the best for a record attempt. You get a bunch of land, but you also get long delays before that land starts contributing tax and manpower; you also don't get new (wealthy) vassals you can imprison and ransom or banish. It's certainly a nice CB and has it's uses, but it's not always the best.
Demesne - "Late game, your capital's importance lies in its"... what? Otherwise, all agreed.
Technology - Legalism matters early. Military Organization matters late. If you're trying for a fast WC, nothing else matters at all. Move capital as necessary. Basically more emphasis on what you were already leaning towards.
Vassals - Agreed.
Building Army - you don't discuss which mercenaries to use. They are not all created equal; in fact, there can be significant differences in their strength from band to band. The Swiss Band is hands-down my favorite 9 games out of 10 - just 75 gold to raise, and they're a very strong unit mix. Also, the holy order upkeep exploit was patched a while ago. If you're in an offensive religious war, you pay holy order upkeep. Period. Doesn't matter if you're also in a defensive one.
Retinues - there's been a lot of talk on this forum about how to fill and use your retinue. You might want to browse some of those threads if you can find them; your advice unfortunately just isn't that reliable. Archers/light infantry cost 1 maintenance and eat 1 retinue cap; heavy infantry / pikes / light cavalry / horse archers are 2 maintenance and 2 retinue cap; heavy cavalry are 4 maintenance and 4 supply cap. What sort of retinue you want will vary depending on whether you're using them primarily to assault holdings or to fight other armies - if the former, you mostly care about their skirmish stats; if the latter, melee stats can also be important. The retinue subunits you describe... I can't match up with any actual ones that exist in the game.
Logistics - this is good advice. I've been mentally wondering if sometimes you might actually raise levies close to the front faster by handing out new county titles to large vassals far to your rear (e.g., make someone King of Norway, then hand them out one county in Sicily if your fighting is all against Africa). I don't know if this would work; haven't gotten around to trying it.
Attrition - your advice is good; you can be more specific about how the supply limit will change if you want to take the trouble to do some math, but I never bother to. 100 heavy cavalry, 400 LC does not really have the strength of 1200 men. They consume the retinue cap of 1200, but that's a very different thing than actually having the "strength" of 1200. Generally speaking, heavy cavalry are kings for efficient use of supply for the purpose of winning battles; horse archers are best for efficient use of supply for assaulting castle purposes. If you're Greek, just spam Cataphract retinues.
Conquering - cutting the connection between belligerents is a rather clever idea I hadn't considered. As has been discussed, 1.092 made truce-breaking a little harsher. Good tricks otherwise.
Conquering by inheritance - Agreed, strong options.
Combat - auto-balance is rarely the best choice. In particular - if you have one general who is significantly better than the alternatives, you should just group every unit under that one general and leave the other two flanks empty. The extra 30% flanking damage is almost entirely offset by the fact that you'll rout the middle flank much earlier in the fight. Also, you should never mix your retinue in with mercenaries and levies if it's strong enough to hold a flank by itself - it's biggest strength is that it is very specialized so combat tactics give it a huge boost, and you waste that if you mix them in with other units. Selecting the right general and terrain is a big topic, but there's a lot more to it than you discuss here. There's some good threads on the forum regarding this. I generally find myself now able to take on armies somewhat larger than I used to, and I'm much more accurate in judging how strong my army really is without just looking at the total number of troops.
Regarding assaults, the first rule of thumb: Be much more eager to assault castles and bishoprics than cities. Cities tend to have very strong skirmish-stage units, which means they're actually harder to take (at equal size garrisons). Pair that with the fact that they lose morale much faster to regular sieges, and it's pretty clear - castles need to die, cities you can often wait out. Second rule of thumb: at least an 8-to-1 numerical edge. They do 15x damage and take 0.6x damage, so if you outnumber them 5-to-1 you expect a draw (could go either way). If you get up to an 8-to-1 edge, you can pretty much count on winning, but may take serious casualties (not always a bad thing, if using mercenaries). 15-to-1 or better is nice if you can get it. If you can't manage 8-to-1, instead split your army 5 or 6 ways instead and simultaneously siege out a half-dozen counties.
Sieges tend not to be worth the gold cost of levies + mercenaries - they earn a little, but not enough most of the time. So I generally am happy to take peace. The exception is when using something like an Invasion CB - if you control a non de-jure holding in the title you're going for, you'll get it thrown in (e.g., suppose England owns Apulia, and you launch an invasion of England. If you accept a peace while Apulia is still under their control, you won't get it. But if you siege out each county in Apulia before accepting peace, Apulia gets thrown in).
Holding distribution - Good advice.
Laws - the other thing to note about Cognatic succession is that if you can manage to breed Attractive into your line, Attractive female rulers will get +30 relations with all their male vassals. This can be... quite significant. CA is complicated. Low is a must; Medium is almost a must (free infidel revocation has so many uses). If you're going to high, you should go all the way to Absolute; in this case, you're relying on the 75% minimum levy set by CA - it often leads to larger levies, but can also cause more fractious vassals due to the opinion penalty. Theocratic Dukes/Kings can help get around this drawback.
Tanistry is my personal choice for strongest succession law, but you have to be a Celtic culture to select it. Otherwise... Seniority has real benefits, as does Elective or Primo. I would have no confidence in picking any of those three as best for a WC game.
Titles - remember that just because you switch titles doesn't make the other title's laws not exist. If you have a High CA title and an Autonomous Vassals title, your High CA de jure vassals are going to be pissed at you even if your primary title is the Autonomous Vassals one.
Council - be sure to have the Marshal suppressing revolts in your capital, and "invite" your potential prison victims to a spot on your council long enough to make them show up in your capital before you imprison them. Early game, best place for a Chancellor is Rome. Mid-game and late-game... hopefully you vassalized the Pope so all those Catholic bishops are paying taxes indirectly to you.
Piety - another point. If for some reason you find yourself at least 10 above your demesne limit, you can buy an indulgence from the Pope for 25 gold. That gives you 25 piety, and +10 relations with the Pope for a few years (that +10 relations can stack, by the way). If you are at or below demesne limit, the scaled wealth cost means it isn't generally worth it. Incidentally, any time you find yourself 10 over demesne limit is also a good time to consider spamming the intrigue invitation decisions to fill up your court with high-trait people for marriages, education, and council positions.
Heretics - You shouldn't get the gold of a heretic within your realm from declaring war. You need to actually imprison + banish them to get their gold. Which can be a painful tyranny penalty sometimes; at least the imprison is no tyranny penalty if they're heretic.
Factions - I had never considered a never-ending 1-Count independence war. That's... somewhat hilarious.
Overall - a good set of tools to have available. Many of them are too much management, or just too cheap, so I tend to avoid them... but it's good to know them. I just don't think, starting as a 1-duchy Duke, you could get a 40-year WC this way. Maybe if you reloaded saves heavily to make sure you got good assassination events and your ruler died at a convenient time. But I'm willing to be proved wrong, if you're convinced otherwise and want to give it a shot.
No offence meant, I apologize.
I was just trying to emphasize the strength of Heir Snatching.. You can get most of the Europe without even a single War but just waiting for old rulers to die.. I discovered this after I had ~1400 holdings, but I managed to snatch nearly every Christian ruler out there and conquered the rest of the Europe without wars.. (Except a few small baronies-counties)
Anyway, comments on your comments are as follows:
Education: I changed my idea 3 times there. First, I went for stats and let others educate them. Then I went for traits and educated them myself. At the end, I went for both.. I realized I could educate the child 5 years myself and 5 years with a high stat Guardian. Most of the traits popped in the first 5 years for me. (Heck, as I played only 80 years and raised kids for ~40 years of that, I didn't have much time to verify how frequent is the trait events, but my last ones were fast).
Pope: Well, as I wrote in the story part, I learned about Invasion CB when I had 400+ holdings, so could never use it. So I could never improvise tactics about it :} But I am guessing I could beat HRE with 200 holdings and it would be a nice jump from 200 to 400.. (Guess it could be done even with 50 holdings and 5k gold, right at the start.. Where to find so much gold so early.. Erm, that's up there :} )
Making Gold: Well, you never banish Vassals. You banish just Courtiers. Courtiers have no banish penalty.. And you can find non-ruler people out there, who have even 500-600g. You can snatch them, imprison them for a legal reason and banish them. Nobody would care.
CBs: After the Holy War, you can grant those lands to simple Courtiers with some gold, making wealthy Vassals. Well, delay after conquest is too long imo, but I didn't care about those lands anyway. Their contribution was mostly to Power and Retinue.
Demesne - Damn typo.. Sorry.. Correction: "Late game, your capital's importance lies in its location and tech levels, nothing else". (Which are detailed above already :} Damned.. I wrote the guide in 20 days, from time to time.. Seems there're some repetitions left among the lines)
Building Army: Well, I calculate the Mercenary strength as per the numbers given in Retinue calculation. (1 Archer, 2 Infantry, 2 LC, 4 HC etc). So a 5k Turkoman Mercenary is worth 10k actually. I keep those in mind while calculating strengths.
The Holy Order is patched? Darn.. Just as I say? They join me while I am defending and I won't ever end that defensive war, but keep them with me indefinitely? (You said "you pay for offensive war", which isn't the case I thought :}..)
Retinue: Well, what I considered to be important in the retinues was the Attrition Limits. Nothing else.. Thus I used all Cavalries, which use large supply/maintenance, but also more powerful.
I've tested this a bit, but correct me if I'm wrong. I can beat a regular 10k army with a 10k Cavalry army without much loss. But if I used a regular army against it, I'd lose maybe 20-30% or more.. So high supply/maintenance doesn't matter for fighting that much. Correct?
Logistics - That works pretty well. I had 6 kings and all of them had lands in Middle-East, Anatolia etc. so I could raise their armies there very fast. No running around :}
Combat - For Auto Balance I said "This is easiest and mostly efficient.", which is correct I guess :} But I nearly never used it. About other options, well I'm yet to read the posts, but I managed pretty good against enemy armies. What is important is really getting somewhere earlier than the enemy and letting him get the penalties. I've even used that for some situations, where I just left 100 soldiers as a bait for a 10k enemy army on a mountain/river pass and on the day the enemy arrived, I raised that County's King's 10k levy on that land, which got all the same defensive bonuses. Just don't forget to assign commanders to the 100 army. They will command the larger army as well..
As for sieging the cities, I opt for the siege gold and re-sieging those lands again. So my choice is cities.. I also guess I gave approximate outnumbering numbers as 6-8, 10+ etc. Lemme check.
Also "Sieges don't give so much gold" is not what I've observed. I've made ~4-5k gold / year just from sieges.. But yes, that's using the "Break Truce", which seems to be fixed now..
Otherwise, you really get huge amounts of gold from siege.. Believe me.. (Works as above.. I had retinues on ships near Constantinopolis, Adrianapolis etc. and I declare war, assault the already depleted cities, get ~150-200gold in a few days, Byzantium surrenders. I start another war for a far away barony and immediately siege Constantinopolis & Adrianapolis again, getting 150-200g again.. This works best when they have a few baronies on my lands, where I can just raise a levy in 0 days.. Seljuks had 5 of them on my lands and I could get ~80 siege gold in 1 day just for sieging those..)
Laws: Well, I want Cognative just to be able to use Female Heirs and snatch them, capture their lands freely too. But I won't have to use that Succession all the way. It's just that, I have to own that title as a secondary. So I can use King of France as my primary, but when I snatch a female heir, I can switch to Navara, grant a Duchy to that female heir and switch back to France. That is very useful imo.
Titles: Well, what I've noticed is, when I change the Primary Empire title, my Levy Sizes changed, so the Laws of Primary Title should be effective on all my subjects. It surely is effective on its de-jure Vassals, but think of this situation: I have Kingdom of X, which has 2 de-jure Duchies, which I keep with Absolute etc. Laws.. When I want to raise the Levies, I make that as my Primary, raise the Levies and switch back to my Medium-Low title.. I'd only need to keep 2 Dukes content and 100% levies.. This is really good. Also, I guess Empires doesn't have de-jure Vassals.. So I can use them as I wish.. (To be more correct, I had Byzantium and HRE and all my Vassals showed under HRE and none under Byzantium. I'd switch to Byzantium at times to use its laws. None was pissed, because it had no Vassals :})
Council: Well, I am comfortable with the idea of sieging a few of my Counties :} Siege gold is gold anyway.. But didn't know that if I used a Duke on my Council, he couldn't revolt when I tried to imprison him.. Nice advice.. As for the Pope, I don't know him
(Conquered his lands at some point and didn't think of Vassalizing him.. Though he hated me.. I am still thinking of a way to steal his 6k gold.. and of Ḥashshashins :} )
Heretics - Well, what I needed to verify there (but forgot to) was if I got the gold of a Ruler that I put out of business.. Otherwise, I snatch them as Courtiers and imprison/banish them to get their golds..
Overall - Just consider this.. I'll invite a few hundred courtiers in the beginning and use the bachelor females to invite a few hundred others (by snatching). I'll then usurp the gold of the Courtiers who try to plot and use that gold as a springboard. I need to get a few Duchies, that's all. For all Duchies I get, I can get another free one using the "Snatching Heirs" method. I also sometimes revoked Duchies and re-granted them to other Duke heirs, so I don't think I'll have much trouble there too..
I'd have to try, but as I managed to get from 500 to 2829 holdings in a mere 30 years.. If I could somehow start invasion of HRE with a sufficient number of mercenaries in the first 10 years, it'd be doable...
Only problem is in that "%50 prestige penalty"!.. :}
