I think if he allows it, it'd be best to tell someone his initial plan in a PM. Then that person create a new thread and become the GM while also playing their character. It'd be difficult but I think this is the better solution besides everyone taking turns plus it'd help, if we do continue, to not mess up his world or just make up stuff and him have to live with it even though he made the world. If that makes a lick of sense.
I, along with a few others were part of the old version of the RP. Unfortunately it only went up to a third of mission 1...