Personally, I am a fan of a mix of RP/Non-RP depending on the circumstances. I used to be a priest in Tera, but became interested in SWG-emu after the blessings / buffs I gave people were made to vanish once they went into a dungeon, since I liked handing out little stat presents, and Entertainer/Officer appealed to me when I read about the classes. I made an entertainer on the test server and am loving the little custom-buff effects in the artiste tree that I can give to people. But since I like helping people and doing that kind of stuff, there'd be a lot of circumstances where someone asks "what is the key to open the map" and it would be (in my opinion) thoroughly irritating were they to receive "what is this map key thing you speak of human?" - a main point about RPing is not being obnoxious about it.
I can be nice to people and give them little dancer buffs, but if someone is looking for specific information, RPing can obstruct it; and those that don't care for it would find it frustrating, which I saw contribute to the stereotype of RPers being unhelpful snobs in some WoW servers. So my rule of thumb is RP until it reaches the point of costing pragmatism, at which point I sortof houserule myself as my character and my character as myself (cause I based my character off of myself) where I can just politely give them information and instructions that are OOC but still IC, sortof... you know what I mean. I guess I consider it a bit of OOC that's actually IC for pragmatic/technical/support reasons, as odd as that may sound, cause I/my-character would try to be helpful and that's an IC thing even if it uses OOC information.