If you are having graphics problems or performance issues, are you running the default option for your graphics card in Il2setup?
If so, you need to select custom (it will retain the options for that graphics card) and when the list of options show up - select S3TC for texture compression. Remove the check mark in Texture Anisotropic Extension box at the bottom right if you aren't using it. If you are using it, stop using it because its going to give a big performance hit. I also use trilinear for the texture mipmap filter because there is no performance difference between that and bilinear on anything above a GeForce 2 (non MX - MX cards are crap).
The Aces Expansion pack promises "better AI", but lets face it - AI is AI and unless it cheats it won't be nearly as competitive as a human or even against a human.
If you want a full realism war, I participate in one that is online. Its into 1942 (winter I think) right now near Stalingrad but its an actual war with either side effecting front line positioning and having real goals to a mission. But don't expect constant action, patroling a target on defense sometimes leaves no action at all for the entire mission time.
-SW