Well, just ran into my first Fallen Empire--they're the ones who don't like you researching certain techs, but I have no idea what those techs are, so could be interesting! I also uplifted a nuclear-age race to space tech and thus now have a vassal state--they're fanatical pacifists, though, so will be interesting to see what they do if I ever actually declare war on anyone.

I also found that when you build a colony ship at a starport in a sector, that sector then owns the colony ship--but they're perfectly happy for you to send the colony ship off to colonise a planet? Didn't quite understand that, they might as well have had the colony ship appear in the civilian ship list as usual since the ship being owned by the sector apparently made no difference.