I still cannot understand how everything works together. I am playing an Ottoman IM game and I was doing fine. I then declared war on Venice and after that it went down hill.
List of crap that my country now has..
bankruptcy
peasants war
devshirme system
provincial govt system
obsolete forces
enforce serfdom
reduced tax income
I'm literally being carved up by the Mamluks and Venice. I don't remember being this bad. My other IM game was Portugal and ive seem to have done fine.
The Ottomans are easily destroyed if you play them too aggressively in *1* direction.
So, early game wars with Venice are a no no.
At most, grab up Byzantium and let that settle a bit while diplo-vassalizing 1/2/3 of your eastern core countries. Then go after someone in the east once a good 10 or so years of AE have worn down from your conquest in the West.
AE is what kills you as the Ottos. You have all this money, army, buffs, big navy, can hire up advisors at the start and go to town. But, you have to spread the wars out across fronts. This is actually, given how AE works, a big advantage because the Ottos actually *have* two fronts. So basically, while AE is clocking down on one front, go fight a war on another front and vice-versa. Better relations over time buffs help with this as well through advisor or ideas, your preference (both is good).
Objectively, the Ottos can build up by simply securing Constantinople, the Greek isles and their Eastern cores and then let things settle down - you should spread that out nonetheless. Once you have huge manpower numbers and some tec over your eastern opponents, basically a time comes when all of the East and Middle East in a coalition against you won't matter. But to get there takes a bit of patience and planning.
One huge advantage, historical or no, is that it's fairly easy while you're diddling a bit in the west to secure an alliance and marriage with Timi. Once you have that, just use Timi to soak up the damage by doing most of the fighting while you stand back and watch and then go in for the kill and the provinces thereafter.
In almost any/every set of recommendations you see in the forums and wiki, there is a, I like to think of it as "youthful exuberance" wherein attack attack attack non-stop is kind of the them. With the Ottos, simply getting some vassals going and later annexing them and grabbing a few cores back puts you into an economic and military position such that you are only getting stronger. In fact, the only thing that can stop you as Ottos is if you help your Western enemies by organizing them into a coalition against you with too much AE. So in opposition to what you'll more typically see here, leave Bosnia, Serbia, etc completely alone. Let them fight it out and have a Bos or Serb blob between you and the west and let the Balkans sort of boil amongst themselves. If you do not make moves to overly tick off the West, it will fairly quickly devolve into fights over chopping up Poland, scuffling for the Balkans, Russians beating on Lithuania's door, France roflstomping Austria, Venice breaking free and getting into Wars with Northern Italy HRE folks and so on.
Another key is this - if Austria hasn't rivaled Venice at the start of the game and it's Ironman, restart. As long as Austria and Venice are rivaled, there will be a Venetian Franco alliance that more or less makes the HRE a mess and you can happily proceed to take all of North and Eastern Africa, the Middle East and India.
With all of the money you get by simply having trade roll into Constantinople, you're easily sitting as #1 in income in the world by a huge margin giving you level 3 advisors across the board, which is an average 50% more mps versus your base numbers such that you are at parity with and/or exceed the Western powers across the board without ever Westernizing (you can typically westernize while you continue to declare and fight wars to the East if you choose). Gobbling up Russia during the late 1500s and 1600s is also nice as well.
But the key is always, do not get the West interested in attacking you through AE. Do that 1 thing well and the rest of the world is your oyster and when the late 17th century rolls around, go roflstomp the HRE who cannot really do anything about it. The Ottos are one of the few countries that can easily conquer their way to 500k manpower and 200 force limit without bothering to get ideas for either.