I know this one has been mentioned more than a
few times, but I would love to be able to check out a skin on an aircraft without having to use some round-a-bout way of doing it (launch, use F3+F8+various keys to get a view). Have an option either in the hanger like a camera sitting in the hanger, or a button on the clipboard that shows up when in hanger that you can click on to give you a good view of your aircraft. From each you can cycle through the available skins. On top of that, have the camera act as a light source so you can get a better view without relying on the "world light" to get a good view. It is a right PITA to check out a skin during sundown/sunup times.
Example of a clickable camera in hanger: