I adore the game and just about everything about it, right now. I can think of ways to improve various aspects here and there, but what I would really love to see right now is just for simple visual pleasure.
Galactic Civilizations 2 has various camera options during combat and other games sometimes include set "cinematic" settings you can cycle through. Example that I'd like to cite is Homeworld 2. One very particular camera feature I'd love is a pilot's view, where the camera is rooted to the cockpit of a fighter or the bridge section of a capital ship. Features to automatically rotate around a select ship or to follow a ship's target would also be fun to mess with.
Just ideas!