Other then ones I've already mentioned.both here and more recently in the Wishlist forum.
More attention made to engine settings. Over work your engine and it blows.
This can be done the same way the auto or manual trim works now. Manual trim and you can fly the plane to its complete envelope for better performance. Auto trim you loose a bit performance wise but you dont have to worry about the envelope as much either
Set on manual adjustments and you can have increased performance with the tradeoff being you can blow your engine
Auto engine and you dont have to worry about blowing your engine but you loose a bit of performance