[member="Tefka"]
As for "how", it appears a straight forward approach would be to simply add another, separate forum along with an associated OOC forum. You could name it Infinities or something, and tag it as the nonSW RP forum. The general community rules would extend to this forum, though you'd probably have a few forum specific rules, such as the "No life guard on duty rule". In essence, you want to keep the OT RP forum as a "side dish", and reduce the moderating overhead as much as possible by implementing rules that encourage a Staff hands off approach
You can differentiate RP threads by genre by simply creating an prefix tag like the ones that exist already, or asking posters to include the franchise name in the title tag.
I'd recommend assigning one current Staff (or recruit a new one?) dedicated to taking care of the administrative overhead of this forum. Duties may include, for example, creating the aforementioned franchise tags as demand increases and organizing stickies or whatever. The Staff person would also adjudicate any truly major disagreements that threaten the harmony of the community.
Those are just some ideas that I thought up pretty quick.