I honestly think that the only "rule change" that college basketball needs in order to be as aesthetically pleasing as the NBA isn't really a rule change at all. It's just to have the refs call fouls in a manner similar to how they're called in the NBA.
Some people love to act like the college game and the pro game are completely separate entities, but the reality is that they're inextricably intertwined. College basketball still supplies the NBA with the vast majority of its players, even if those guys only play in college briefly. What that means is that the majority of players are going to arrive in the pros with an understanding of how to play that's based on the college game. That's what their instincts are going to be, and that's going to be what they were taught. Whatever differences occur are going to come about because of changes in the circumstances they're playing in. Some of which is, yes, in the rules, but a lot (I would say most) of which just has to do with how refs call fouls.
The college and the pro game generally followed the same paths until about 10 years ago. Those paths had, for a long time, generally been ones of ever-increasing physicality on defense, slower tempos, and lower scores. But the NBA acknowledges itself as a pure entertainment product in a way that the college game won't admit, and the NBA recognized how that trend wasn't healthy for the entertainment value of its game. So it made a concerted, pretty successful effort to change that trend, with a few rules' tweaks, but in large part by forcing its refs to call hand-checks, arm bars, shoving off the ball, moving screens- just a lot of the stuff that clogs up the game and tends to turn it into a wrestling match.
The college game has not followed suit. There was a stab at in 2013-14, but it lasted about 2 months before reverting back to the status quo. And the result has been ever-slower games, with ever-lower scores, with little ball-movement or offensive flow. Call fouls like the NBA does, and I think that changes, regardless of whether the clock goes to 24, 28, or 30 seconds, or whether the illegal D rules are the same, or any of that stuff. Officiating is simply the biggest factor.