In Summits, you can take a new Negotiation action, Broker Peace: Flip a Ceasefire token from War to Peace, with the consent of players who control at least 2 systems in total in that cluster, including yourself. You may get the consent of Rivals by returning 1 Favor of theirs.
You can return Favors to gain consent from Rivals who control systems even if you didn't call the Summit.
During Summits, the First Regent controls Empire-controlled systems.
Act: 3
A: Nope!
A: Yes! You just need the consent of either of those players.