I did exactly what you want to do, and I can tell you what was right and wrong with it. I was building guitars at 16, and I was recruited right out of school to a large guitar manufacturer for R&D, marketing, sales, and to build custom instruments. I don't regret it, because I felt like I started my life's goal sooner than others did by bypassing useless schooling. I was very self motivated to learn and hone my skills. I am very good now, and have been for quite some time. Let me tell you what the environment is like for me where I live. You are either a hack, who does poor work cheaply, or you are good, but you still have to limit your price to be competitive with the hacks. Or, in my case, I have had to limit not only the number but also the type of people I deal with. I am very selective of my clients because I don't do what other techs/builders do. But I couldn't have gotten here without working among the former two categories for a long time.
To make a name and money, and to hone your skills, you will have to do service work for awhile. That's why I didn't speak directly to "luthierie". You can't ignore the repairs and go straight to building, because by doing service work, you see what other manufacturers to incorrectly. And you'll see, to the smallest detail, what you must do differently. There are too many things that aren't in any of the books or videos I've seen. I worked with someone who went to luthierie school and only received a basic knowledge of guitar construction, with no development of his eye, or motor skills to go right into regular building or repairing. It takes time.
Also without a degree, but with a wife and child, my situation is very limited now. It's been difficult to balance making money to support a family with my love of luthierie. If I had a degree, I could make a high level income, provide for my family, with time to spare for luthierie. So I had to do things outside of college to gain the education and licenses to do what I do in the financial industry now to "provide for the family". As it stands, I can't see getting back into full time luthierie and ever making the $90-130k per year that you need to really do right by a family in these parts. I mean provide a nice lifestyle, savings for college, savings for retirement, etc. And those are things that I want to do-even more fervently than build yet another guitar. So my life as a luthier who has time now to build what I want and for whom, would still have been improved by the presence of a degree.
Stay in school, poke around with guitar repair and building, and learn business and finance. Those things are infinitely more important than your skills as a luthier. If, by the time you're in your 20's you have looked at business models and you think you can make a living doing it, have at it. But you need something to fall back on. None of us knows how children age 8 and under will feel about wooden guitars. Technology is changing so fast that a Parker Fly concept, that is, just mold the guitar as one piece on an assembly line could make that generation happy, even though this one prefers luthier built wooden instruments. The electric guitar is only 60 years old for crying out loud! Would you build a career with that kind of track record without knowing you could do something else if you had to?
I've been guilty of long posts in the past, but this is a serious enough topic to warrant it.
Forgive me if it's harsh, but you're better being safe than sorry. Others may say follow your dreams and don't listen to nay-sayers. I agree with that philosophically, but I think finishing school, and getting an education in the raw science AND business of guitar making is all part of that dream. I jumped the gun. I went early because I was good, and the opportunities were being thrown at me. And although I don't have any regrets, I am paying the price for it now.