I hate that we can't just make university students like in Sims 2.

But you don't have to have them earn skills and work? Don't get me wrong, I like very much how 2 had a contained university. 3's, too, frankly. Much better than 4's integrated world. Last I checked, though, the development is unnecessary unless you are going for distinguished degrees, scholarships, etc. So extra on top of just the university experience.

The most I remember being required to wait is for the acceptance response. Beyond it not being that long, you can force enrollment with cheats in 4.