[oh2bpreg]

But open roleplays may eventually become closed roleplays once a certain number of people join.  Would be a pain to have to move the thread to another forum when that occurs.

I think if whoever starts the role play has the intention of marking the thread as closed once X number of people join, they should just start it in the closed section. They can even mark in the title "X slots available until closed." I think it's more about the end goal, not how it starts.

But then you're creating a problem where open threads won't get filled because no one is going into the "closed threads" section to look for an open forum.

It's really not that hard to find an open rp.  

Go to the rp thread section.  hit ctrl+F, type "open". hit enter.  hit the down arrow to scroll through open threads.  Lather, rinse and repeat on older pages.