As for NPC interaction, trading missions might be fun.
Sure, I can see how sending out salvage ships with tractor beams dragging ruined vessels to a starbase for repairs are interesting; Or having small repair drones fixing the engines etc.
I don't think it fits my play style, but once docking and tractor beams becomes a thing, you can always at least roleplay that.
Some gameplay switch where your crew actively has to repair stuff might be a cool option though. Still, it would be weird to have to repair stuff over time that you can build from scratch instantly.
