Nopke's mod stops the WANT to go to college, but it doesn't (?) stop them ageing up and crying because they didn't go to college..which is what really bothered me.
As for the "try it a see" hahah no

there have been a few times that I've wished that when you had a teen runaway it put them in their own household in the sim bin .. if you exited the lot and didn't bring them home .. though maybe get a message askin first what to do with them.. for them to "stay" on the lost, but can still be ran away .. or "leave" in which they'd get their own household

If it was your only playable sim at the time, it might work like death? My vampire sim got killed on a community lot by being poked by an angel (You know how it is!), and they were my only playable, I basically ended up left in edit lot mode, with the only option to be go back to neighbourhood (without saving).

I didn't save and my vamp was back home, upon entering their lot they just did the usual return home thing.