As for pros using the 10 finger grip, I found this with a quick google search:
I think I read once that a great majority use the overlap, but the interlock is very common as well. I think the same article also claimed that interlock (and maybe 10 finger as well?) is more common on the ladies tour than the overlap.
Just finished taking lessons, and at the beginning of my lessons my instructor asked me what grip I used. I said interlock, and he said because of the size of my hands he thought I used either the overlap or 10-finger. But he said any grip was fine and "It's all about what you feel comfortable using."
I tried the overlap -- didn't like it. Tried the 10-finger -- didn't like it.
My golf instructor was great (and he is a well-respected instructor), so if he said grip doesn't matter, then I believe him.