That is really interesting. I wonder what will happen in multiplayer if I decide to be the villain and the rest of the party plays good?
Probably something similar to what happens in a PnP game when one player wants to play differently from everyone else.
Unlikely. In PnP, that causes massive problems for the DM. Here we don’t have that limitation.
Unless I am mistaken, this isn't like Divinity 2 where it's a competitive environment and anyone can 'win' the game, but I believe whoever the host is, they are the main character and it's their story and other players are just along for the ride.