As far as balance goes, I can't give you an accurate answer because I'm the 3rd owner (plane is at least 10 yrs old) and when I got it, it had a piped K&B .40 on it that was very unreliable. I just put the TT (which is actually an early Magnum Pro .46 SE that became the TT Pro after the conflict back in the 90's) on it and balanced it at the main spar. I've never flown or balanced it with any other setup.

As was mentioned, a beginner doesn't really notice monumental differences in a prop-size or two (at least I didn't, anyway). I started with an 11x4, broke it, and went with the 11x5 APC at my instructor's suggestion. It does seem a tad slower on landing and has plenty of power when needed. I still keep 10x6, 11x4, and 11x5 in the flight box, though.