You shorten it and it becomes a huge disadvantage for the mid-major and less talented teams. That's part of the beauty of college hoops...there ability to compete in a one game setting.
i vote no on the 24 clock for the NCAA men's game. i like the way 35 opens up the game to a lot of different tempos and makes teams play D for the full 35. 24 you just get guys dogging it back and forth a lot, at least in the NBA reg season.