Why not start at a community college now? I wish I would have known that was an option. If you can show them that you are motivated you can take a couple of extra classes and college classes while more intensive than high school classes are much better for the most part.
Nope! Just go and talk to someone, seriously mostly you can do this stuff if you just go and get in the door. Tell them you are interested in taking some classes at night in addition to high school (if you are). Your counselor might be able to help you with this too, mine wasn't very helpful, but if you want to do it I'm sure you can. In fact, I can remember twice in college where there were high schoolers in my classes. I asked one of them how they ended up there and he said that he simply annoyed the admissions office into submission. I'm not trying to force you to do it, but the option is definitely available.
You didn't ask the right question: "Is getting an associate's degree for free a good idea?" FUCK YES IT IS. My recommendation: get an associate's degree in something that will provide you with a job you don't hate and that will most likely lead to gainful employment. Spend the necessary time pursuing that associate's degree to reach out to employers in areas you'd reasonably want to live so that when you're done with the degree, you're in a good spot for a journeyman/technician job. Work at that job to see what you like about it and what you don't. See what sort of education you need to advance to the next level - at this point, you're a degree, several tens of thousands of dollars in non-incurred debt and a year or two of experience ahead of your peers. Improve your standing with online education or night classes and get your employer to pay for it. You're now another few tens of thousands of dollars and another few years of work experience ahead of your peers. And you're probably driving a car that doesn't suck and living without six roommates. By this point it's probably 2020 or so, you likely have a bachelor's and a few certificates, and the whole clusterfuck that is the American higher education system has probably settled down a little bit. And that's the big thing. Getting a 4-year degree right now is a lot like buying a house in 2007. You're going to get fucked. The system is experiencing structural change and that's a great excuse to stay clear of falling rocks. Read this book. It's a great overview of the level of disruption higher ed is currently experiencing, as written by the editor of the Chronicle of Higher Education.
To echo kleinbl00 below me, not only yes but FUCK YES. I never went to college, and even though I have scars older than your parents and more than 20 years in the computer industry doing work that most people don't even read about for years after I get proficient at the work, not having a piece of paper holds me back and hurts when I drop resumes. I make great money, but not having that piece of paper is probably costing me $20K a year in salary. You get a two year degree that should be transferable, no debt and a leg up on your peers. Do it.
A lot of the community collages have dual enrollment or a specific high school program. I had to take all my history classes there because I was taking 2 video production classes in HS and I was overflowed even with zero period. The best part? Those community college classes counted for my high school diploma but my college also took those as credits. Between those and a couple AP classes, I had my humanity gen-eds 100% done before I got there. Look online at your local cc's website and look for high school programs or dual enrollment. Or hit up your counselor or whoever at your high school. The programs are pretty secret - I only found out about it because I couldn't fit all the classes in my schedule.