Just a few thing i was thinking of and didn't see elsewhere
The logistics system- I always felt it was boring. Do you guys at StarDock have anything new?
Ive heard a lot of people talking about a carrier module, but not really balanced. What I'm thinking is that there could be a module that takes up like 90% of a giant ship, but reduces small ships to 1.5 logistics points and tinies to 1 in the fleet.
More galactic wonders- There were only a handful on gc2, but they were really cool.
Natural wonder type things- just extremely rare but powerful formations- like maybe a habitable planet in a binary system, giving extra defense.
Stars- I think ships stationed directly next to stars should be damaged a bit per turn.
Different kinds of engines- Maybe a kind that instead of adding 5 movement per turn adds a random amount between 1 and 9 per turn? other kinds also