Yep, the whole thing with RP is to do/be something you are not... to step out of that. I do it by stepping out of my human skin, you do it by stepping out of your gender. Great way to build yourself up as a writer.
I second the whole "research" thing... I've been a scifi/fantasy reader from a very early age, so I know how helpful it is to study the "Masters". Read the kind of books you want to write! Same with the RP stories you want to tell.
It would also be tremendously boring. I RP as alien/fantasy critters for that reason, because I have not only no interest in RPing as ME, I have no interest in RPing humans. Because I am one. And that leads to:
Exactly! Only I take it one step further. Going not only out of my gender, but...