I have a curious question about running more than one character:
Is is possible for a single player account to have more than one character assigned to them? If so, is it possible for a single player account to have a regular character and also be a GM (or Co-GM) in a single game?
I think the later is possible, but I am not sure about the former. I haven't tried it on my games yet.
Both are possible, yes. They are set up from the GM Menu in a game, using Edit Characters screen --> Add (Existing) or Move (Existing), depending on whether you want to create a new character, or transfer an existing character.