I know this is a really old thread but I'm unable to find any real information about my question aside from this posting.
I've had a working config for Mario Galaxy 2 for awhile now, but just recently started playing again. I came across the level called Silver Chomp Challenge or something, where you are on the ball. My problem is that the ball requires the Wii remote motion for turning left and right, as well as keeping it pointed upward or something. I had my mouse doing all the work for the pointer and motions, but I can't successfully maneuver the ball to beat the level. What did you do for that kind of setup?