Hey Jace,
I'm 18 now, just starting out at the U of O.
When I was 16 I soloed the JMT. And I was planning to do PCT in 2011 but my parents said no.
The AT? Do it bud. Plan it. Be smart. Bring a SPOT to appease the parents (and update when it's clear!). And hike it! I wish my parents would've let me take time off, but that wasn't the case. You've got gold my friend. And if you're ever in CA during summer, let's hike.
Ben
Edit: with the permits, I've always found them to be… well I never had my ID checked! But I echo: Be smart! And like Roger said, try a couple solo trips first. I didn't do that, and learned a few things on my JMT hike, luckily I wasn't slowed by them, but sped up. Try to eliminate surprise by practicing, though.

