I would probably get rid of the last two minute replays to determine possession. I don't know how many times I've seen them call it the 'right' way, when there were obvious fouls involved. They should still just leave it to the discretion of the ref.
I also don't care for the intentional foul technical in the last two minutes.
Ehh the Intentional foul in the last two minutes prevents the hack a whatever from dictating the whole game.
Don't get me wrong, I don't mind the hack a whoever strategy and if your guys cant hit free throws then they shouldn't be on the court but I still wouldn't want to see the strategy used the entire 4th quarter or with the game on the line.
Maintain consistency of personal foul calls. You can use your body a ton in the block if you're over 6'6'' but a hand check gets a foul on the perimeter. Makes no sense.
It's be interesting to see what would happen if goal tending was relaxed in some way.
Shot clocks for free throws and/or make it one shot and the ball on shooting fouls.
By far and away, though, it'd have to be (for college) to shorten the shot clock to 30 seconds.