This one will be VERY controversial, but figured I'd make an official wish out of it:
A major advantage we cartoon pilots have is the ability to make out controls much more convenient than they would have been in the real aircraft. There's no need to reach around to flip switches because we have everything a keypress or, even better, a toggle on our stick or throttle away. It was discussed over on the Aircraft and Vehicles board that this has led to a number of aircraft being used in ways that just wouldn't be physically possible in real life, because the real aircraft might have controls positioned in places that would make performing multiple functions simultaneously impossible. IE: adjusting trim, throttle, AND flap position all at the same time.
The wish would be that each aircraft have a delay when the button for certain actions are pressed, before the action is actually performed. The length of this delay would vary based on the "neutral" hand position (IE, assume stick and throttle for all functions) with a modifier that increases the delay when the action is performed while pulling Gs.
For example, using the Corsairs (one of the popular subjects of this, and also the plane I have the best idea of control layout for) as an example:
It's physically impossible to manage throttle, flaps, trim and drop the landing gear at the same time the way players do in the main arena. This is a sizable contribution to complaints over the F4U's flight modeling. Adjusting trim or flap position would require taking one's hand off the throttle, not to mention it would be extremely difficult to do while in a 6G turn.
The delay for each control would be specific to the aircraft, based on their internal layout. Additionally, as a compromise, aircraft that had automatic flap capability (IE, the flaps on the N1K2, or the ability of the F4U and F6F's flaps to "blow back" and drop automatically with airspeed over the first two notches) would receive this capability.
Additionally, to prevent "chaining" commands, trying to perform a second incompatible function while the first is waiting would override the first command.
In other words, player hits the toggle to adjust pitch trim. During the delay, he decides to drop his landing gear. Instead of first trimming the nose and then dropping the gear, the latter overrides the first command and the pilot goes to drop gear instead.
This will significantly affect the way a lot of aircraft are used, and even small delays might be enough to start seeing aircraft flown more in line with the way they were historically, since constant manipulation of flaps, throttle and trim would no longer be possible during the middle of a fight.