I was wondering but there's no currently included win condition for Culture, which was one of the more unique elements of Sins which seems to have been forgotten.  I believe that there should be a win condition for having enough culture spread.

Also, I would like to see the ability to set the player's slot to a computer so it's possible to observe AI-only rounds to observe and learn the gameplay as it actually takes place, or as an ability to analyze how the AI works in depth with a spectator mode for when there's no human slot in single player.  I would also like to see the ability to play a hybrid slot (either with a computer or another player) like what you could do with the original sins of a solar empire when you changed to a computer's slot while in game.  Only in this case the AI doesn't argue with your orders quite as much if implemented.  I think it could also lead to interesting matches with two players managing the same empire.