As I was playing the newest version of Starfarer (sorry, Starsector) I had a few ideas about possible features for gameplay.
1. Mining resources from asteroids and planets to use in terraforming (see point 2)
2. Terraforming planets to increase denizens, allowing the planet to produce resources on the nearest outpost. (Terraforming another faction's planet will decrease relationship with that planet)
3. Building outposts with a set amount of resources ad placing them in space or next to a planet.
4. Assigning officers to certain ships in your fleet to allow them to control those ships seperately.
5. Allowing the player to split up/conglomerate their fleet among the officers and outposts (i.e, the player could be attacking the pirates on Corvus III, whilst a detachment of frigates, fighter, etc. defend the abandoned storage facility and the planet.)(However, the player needs officers to supervise the detachment.)
6. Missions (such as courier/delivery, escort, search&destroy, etc. from factions to improve relationships)
7. Relationship with faction determines the price (i.e better relationship=cheaper, worse relationship=more expensive)
Those were just a few ideas that I had. I'm not sure if anybody else likes the sound of these ideas, but they seemed pretty cool to me.