I've found the best way to figure out combat weaknesses is to fly the planes yourself and figure out their best corner speed part of the envelope at the best altitude, by timing several maximum sustainable rate 360 degree turns. Then, engage in the best part, and avoid combat in the bad part, taking into account the enemy aircraft's envelope too. After all, you've gotta be able to see something in your gunsight first before you can hit it and worry about what bit to damage! So an afternoon's worth of 'test pilot' experimenting is time well spent if you really want to exploit this kind of detail, doing this certainly pays dividends if you like dogfighting online.
But if you can't be arsed with all that, you could just go with the earlier FW-190 variants, they have among the best instantaneous and sustained turn rates, and in theory are able to sustain more damage too with their air-cooled engines, as there is no coolant system to get knocked out; which is a major weak point on aircraft powered by in-line liquid-cooled engines, both in real life and in IL2. If you like head on firing passes, it's a good choice too, particularly if you are not good at deflection shooting. For a 'boom and zoom' aircraft that is good at this, try some of the big Russkie radial engined fighters.
Unfortunately, although the damage modeling in IL2 is quite complex, it often doesn't compare with the real thing in some respects; you can invariably see aircraft in IL2 lose a wing and have the wrong type of wing spars modeled, for example. Most of the 'original' IL2 aircraft fare better in this respect, some of the later add on '1946' stuff is pretty basic as far as damage modeling goes.
In theory, the Sturmovik should be one of the toughest in the game because of that, with more 'systems' going before something terminal develops. Luftwaffe pilots used to call it 'the cement bomber', because it could take so much damage - they sometimes would try and shoot the elevators and horizontal stabiliser off it if they could, so that it would go into an unrecoverable spin.
Conversely, the vast majority of the Japanese 'Pacific Fighters' stuff should go up like a leaking Zippo after a couple of bursts (and does in the sim), as they often lack self-sealing tanks. But with such a light wing-loading, turning with them is tricky in a big US fighter, so if you like the big Yank stuff, getting good at long-range delfection shooting is something worth perfecting. The exception to this is the P-40, which can hold its own in a turn with Jap stuff at low altitude if you fly it right, and it can take a fair bit of damage too, although you need to be a decent shot with it, as it is a bit undergunned.
Chock