sheesh....
I'll answer the question from my perspective. Obviously, I can't answer it from RG's perspective.
RG asked 
1) Girls of MSF, 'fess up - are you shaven?
Yes I am. (Of course, YOU knew that!
) I shave completely down there.
RG asked: (2) If so, why do you do it/like it? Does it relate to your spanking kink in any way (or, at least, in any way that you'll admit )?
I dunno fully why I like it. I did it for my ex once, thought it looked totally silly, and said I wouldn't do it again. But then my first spanking partner liked it as well, and I did it for him once, and I've just kept it that way ever since. Now I like it - and think that hairy muffs look odd. (Nothing wrong with them - just they look foreign to me now)
Altho I initially shaved it as part of kink play, that isn't really why I like it. Hair feels....I dunno, messy. Shaving my muff makes it feel smooth, and the sensations during erotic activity is increased, which is the real appeal. I like the way it looks now, too.
sarah