I actually have to opposite problem with CPU homeruns. I play with the AI batting power on 90 or higher because they rarely hit anything out of the park. I think a lot of that has to do with the pitching being to easy though. I can always nibble with amazing accuracy so they don't get any good pitches to hit. It messes up the balance of the game.
I do like the rest of 2K10 besides the other problems you mentioned. I think VC did a pretty good job and I think they will keep improving it this year. I'm looking forward to seeing how it turns out.