I'd prefer this too, but I'm fine with it being 30 seconds. Having 5 less seconds to set up - and reset - an offense is a much bigger change than most fans realize.
But defensive 3 seconds really should be added to the college game. Players are so freakin' athletic these days, but that athleticism is largely negated when a 6'10+ foot centers are allowed to park themselves in the paint. Defensive 3 seconds is a great rule that a) forces people to play defense, thus eliminating many flop attempts, and b) adds a lot more space for talented offensive players to operate. (It would also be another crushing blow to Syracuse, which is an added bonus.)
There should also be one fewer TV timeout per half, but that will never happen for obvious reasons.