DD is currently a freshman, and started the school year as a 16 year old. Early on we had hoped to push for a gap year/foreign exchange to delay her entry into college, but she was adamant about getting to and through college (and med school) as early as possible.
Currently she's at a small LAC about a 5 hour drive away. Far enough that she's on her own, but she also knows we could get there if we needed to. So far things are going fine. Most instructors/students don't know she's that young when they first meet her. I think everyone assumes if you're there, then obviously you're "supposed" to be there.
The mental adjustment was probably harder on us than her, as she's been with older kids for years now. And part of the reason her skips have been so successful is because she is mentally and emotionally older than her age.
So far the only "legal" issues we've come up against were her inability to participate in a "mandatory" survey given to all freshmen (over 18 only) and that her NCAA drug testing consent form needed to be sent to us to sign.
She was a little disappointed when we said we were not going to allow our 17 year old to go to Mexico with her friends for spring break, but she understood. I did explain how her being 2 years older would not make me a whole lot more in favor of a trip to Mexico.
Best of luck,
--S.F.
