[quote=@RedDusk]
Honestly, in my experience, if we move too fast, ones who post slower might lose interest and quit. It happened quite a lot to me actually, so I think I'm gonna take my time a bit.
[/quote]

I'm definitely of this opinion.  Some people can't post as fast as others, and if you speed ahead of them they'll lose connection to the plot, and then lose interest in it.  

As for collab posts:  I love using google docs for it.  You can set it so that anyone can edit it, and just post a link and you can actually watch as everyone edits it, allowing you to collaborate in real time if everyone's on.  Or, if only one person is on, they can add their contribution and be on their way.