Oh hey! It's you! Haha! Thanks, dude. Game is great. It acutally is a lot like I expected EU3 to be. And muslims, urgh, as Portugal they are right on your doorstep, tho it seems they have plenty of conflict among themselves, too. I guess this keeps me more safe than I realize.
It's actually not that complicated, that's why I really recommend the in-game tutorial as boring and not pefect as it is, because you don't really really REALLY need to know every system and how they work, you only really need to know what each of the 300 buttons, do. So when at war, just go to the military screen and there is one button there where you gather an army from each vassal (including the one in cities inside territories you own) and one button to gather an army from these territories you directly own. From there you just gather everyone in one big stack of death and stomp people as they come. That's the basic, you can obviously be more effective, but I don't know if the game ever demands it too much.
There's a more complex math regarding armies (and other systems), but the game doesn't punish you too much for not knowing them. You really just need to know what button to press to do what and this the tutorial explains.
Sounds very random. My character got ill and better at least 3 times before one disease finally killed him. I think it might be related to how he was personally going to wars, but I don't know. These paradox games do an actually goood job of turning a gazllion of different events into some number somewhere that can be min-maxed if you're neurotic enough; but in the case of this first game of mine, it seemed I was reacting more than causing the little things like sickess and intrigue.