About the non-existent fast break you speak of, I get a good 5 buckets on the break every game.
As for the missed layups, it's realistic and I'm glad we don't make every one. Watch an NBA game, you obviously get frustrated with missed shots inside, and it happens more than twice per game.
Pass out of the double-team quickly.
Obviously the AI isn't going to cut unless you tell it to. If you don't run any plays or use off-ball control, of course they won't get open. Also, Pierce got called for 3 seconds last night when KG had the ball at the top of the key. It happens, and rarely in 2k8 for that matter.
About the dribbling contact... well, that's realistic. If you want to go around your defender after a pump fake, run around him, not through him.