Couple of ideas i was thinking about while playing tonight,

First being a starport style platform.
While slowly upgradeing my fleet of 20 Anubis i felt it was pretty slow so what i propose is a large platform with 20 docking berths, You can select to have your entire fleet dock. In addition to being a harbourage it would allow building 2 Shipyards and a supply depot.
Finally you can select to retrofit all docked ships (Of the same size) with the same parts all at the same time.

Second would be a Supercapital Carrier, Something you could use as a flagship. It has no weapons but carries a regiment of fighter scale drones or fleet support drones depending on your preference. Catch is you can only have one of this ship total. It is too big to dock but can use cargo drones to transport any cargo between it and stations.

Thats my main 2 ideas atm but just had a 3rd.
Be cool if there were 3-4 times the current amount of worlds, moons etc, maybe an additional system. Goal being they are somewhere to expand too and add some late game competition with the NPC factions.