Comments on your recommendations in detail:
i) Diplomacy and trading. Not possible, since the AI will consider many factors before deciding on a specific trade agreement. Also note that you can buy multiple kinds of resources in the same agreement, and you couldn't take that into account.
ii) Map inaccuracies are abundant and can be rather annoying, yes. I would suggest using a map-mod
iii) There are only a few scroll-bars that are wrongly placed (and those are not even used in vanilla to my knowledge), and there is only one I could think of that is missing: the one for scrolling through multiple selected units. But you didn't have enough units to have trouble with that, so I wonder which scroll bar you were refering to?
iv) The sliders. Did you know that you can right-click on them to lock them? I don't really see how you could use the arrow keys unless you somehow select a slider first to tell the game which one you want to effect with the keys...
v) That was a very annoying problem early on, but it is fixed now. 1.4 helped a lot, and I rarely run into such a problem in Semper Fi.
vi) Oil is intended to be only used to be converted into fuel. Fuel is intended to only be used for powering aircraft, ships and certain land units (the ones with vehicles). That of course doesn't mean that your nation does not use any fuel if you don't have such units, but the civilian usage is outside the scope of the game. It would add a level of detail to include those, but also a lot of micromanagement. Again, if you don't use fuel, you shouldn't worry about oil either, but the automatic conversion from energy to oil can be frustrating.
vii) The "Nationalizing the Private Sector" is a completely random event. Also note that it was
not done in '17 at all. I assume you know about the six years long civil war in Russia
Even after that, communizing was not done overnight. And again, random event.
viii) To be honest, I agree with you here. I find the working of this event pretty stupid. There should be an alternative option in the very least, and I would rather give a flat increase in Dissent instead of an increase in Dissent gain. Would make more sense.
ix) Could be interesting, and hopefully something like that might be included in the second expansion, which promises to give depth to politics and diplomacy. We'll see.
x) There are two non-obvious ways: a random event for a democracy to turn into an autocracy (Fascist and Nazi version) and another that will practically never happen, but could turn a non-democratic nation into a democracy. They have nothing to do with policies or laws however, only the government type, the ruling party and their organisaiton (plus NU and dissent).
xi) I agree here. The alerts should be possible to hide.
xii) Production Efficiency actually decreases the IC cost and time for stuff in your production queue. The point here is that they don't increase your IC, only it's efficiency. The other industrial tech, which increases your IC also increases the amount of resources you need, which might be bad for you. Research efficiency is similar: it doesn't increase the available Leadership, "only" makes research projects faster. Neither of them applies on a provincial level.
xiii) See above.
xiv) The AI in Semper Fi is improved for them. Sweden might still find itself involved if the Germans want to get their Steel mines though.
xv) They should, and they probably do. But by that time, the UK probably have enough forces to hold them off indefinitely. In vanilla, the sub-warfare part is not really balanced that well, and it is impossible to starve the UK. Without that, they will be able to protect their islands. And they should be!
xvi) I'm confused about this one. Do you mean allies not involved in the war? The AI
can't go through them. Or allies involved? The AI
does go through them.
+1) You mentioned the Axis nations not being involved in the war. That is intentional: the Axis has a "special power" called 'Limited War', which means you start a war without involving the rest of the faction. That represents the separate wars in Asia and Europe, and Italy's late involvement in France.
+2) You also mentioned the lack of technology exchange. That feature from HoI2 was replaced with Production License. You can't get the Infantry techs of Germany, but you can build Infantry with German techs for a small fee. You should try it sometime
+3) The Monroe Doctrine is strangely implemented... It
should involve all of America, including the Carribean. That is most likely an oversight.
+4) You can build individual battalions of MP, only they can't really do much. There's a button in the Production screen under the "Create Division" button. That will allow you to build any brigade individually. You can't add a leader to individual brigade though, since the game only has leaders from Major General and up. If it included Briagier Generals, the number of leaders would jump from a about 5-10,000 to 50-100,000. You don't want that
I hope you don't mind this wall of text and I also hope you learn something new from it
Also congratulations on fulfilling your objectives!