This is just a small suggestion but I've seen it work well on other forums. I would suggest creating two new sub sections of sorts, one for regular SFW RP and then a second section for NSFW RP, and then adding a few new options under them as a means of further organization.
So for an example for the SFW RP section you would have:
SFW Open Roleplays - Where the actual RP's go.
SFW Private Roleplays - Roleplays that you have to request the OP or Gamemaster to join
SFW Brainstorming/Recruitment - so we can discuss ideas and find interested partners
SFW OOC Chat - a place to discuss an ongoing story, its plot, what we like, and what we don't.
These sections would also be duplicated of course for the NSFW Roleplay section. Another thing to consider though might even be to create an additional section which would add five subforums, but this last one is really just an after thought as I type this. So it would look like this:
SFW Open Roleyplays - See above
SFW Private Roleplays - Look up
SFW PbP Roleplay - Post by post, which refers to more structured RP using a system DnD, D20 Modern, World of Darkness, Savage Worlds, etc.
SFW Brainstorming/Recruitment - Look higher
SFW OOC Chat - Yep, you guessed it; look up.
So the way I imagine it the forum sections would go something like this:
SFW Open Roleplays
SFW Private Roleplays
SFW PbP Roleplay(Maybe?)
SFW OOC Chat
NSFW Open Roleplays
NSFW Private Roleplays
NSFW PbP Roleplay(Again, maybe)
NSFW OOC Chat
Now I realize that this isn't primarily an RP site, however my suggestions really come down to the fact that I am an absolute stick for rules, regulations, organization and everything in general that represents order. Mhm that's right - Lawful Good.