If I could add one thing right now it would be making sure the complete aircraft is rendered when I am in the virtual cockpit view. I have noticed a few missing noses and outer-body textures as I look around. This doesn't really come into play if I am sitting where I should be, but the missing noses are very obvious when landing and I sit up tall to look over the dash. I also like to stick my head out of the aircraft and look around sometimes.
Other than that, I couldn't really think of something else I would want, so whatever else you add is great to me