While I am a relatively "newbie" in the Game (I've actually played off and on for about 3 years (Argent, 3031, and Zexx)) I think adding a click-able cockpit defeats the purpose and intent of the game. While Aces is intended to simulate realistic Flight in Piston engined fighters; the balance between realism, complexity, and instant Action game play would be undermined by adding this feature. It may even handicap the game entirely.
Honestly, (and I probably ill informed about this) many fighters had to be primed by rotating the prop so that the engine would start. Some Early Spitfires were among this case as was the Me-109 and even the Fw-190.This being the case it would add to the complexity of the game by having to initiate a "start up sequence" just to get in the air, and I don't think you can simulate Ground crew starting your prop with out adding a cut scene. ( although I would do it myself if I could do so in game)
This is just my opinion on the subject ( as useless as it might be:P)