I think this is a great idea! And can't wait to give it a go. The one thing I'm a little worried about is the leaving a party, since you can't actually leave a PM conversation...

Also, for the chronology, there was an rp I was in where every post would have the current time and place of the action occurring and if it changed, that would be clearly stated separately from the IC text before the post continued. That would probably be helpful here, at least, mentioning the time. That way it isn't all on our GM to keep track of that as well. Though I'm not sure how specific we'd want to be about it. Whether just saying something like evening, or morning, or maybe 1 hour from arrival(though I think they aren't all arriving at the same time, are they?) Anyway, if that can be figured out satisfactorily for everyone, it would probably be a good idea. :) Having the time markers, not necessarily what I just said. ;)