I am really hyped for the research system - would be great to see that work out :)
For stuff i am not entirely sure, u havent planned yet... i was thinking of advertisment, to boost your economy.
The idea is, beeing able to build (or rent) gigantic ad-tablets or cubes, floating in space and showing your message, like: "unbeliveable engines to buy at my homeworld... 233 - terran9"
Another thing that could get implemented, is the revenge-system i know from Age of Wushu. If u get killed off there, u can pay an NPC to annoy that player in a way u want it. (disturb training, attack when crafting...)
With our NPC-races, we could get that going.
Options like "attack transporters", "terrorize planet", or "attack playerX, when in fight" could be fun. Haha, but i guess, u have already planned that, havent u?