Would all a race be under one controlled organization? Would later multiracial organizations develop? Primitive races joining your faction? Be nice if there could be more. System councils and officials to govern (taxes, spending, building) over specified colonies/colony (named by user). Discontent ones revolting to go on their own, creating their own government. Depending on governemnt type, you have less/more control and appointment power. Your officials and system councils going at it. All bribe open to other powers.
Business, crime, party, and discontent organizations controlling planets, ships, trade routes. Power governed, or not (so many ships, trade lanes, contribution, etc), or just not obeying. Supplying information?