Should I stay in school?
I know from all too personal experience that it the easiest thing in the world to say "I could totally ace these assignments if I tried, but I can't be bothered to try." Talk is cheap. You may be different, but when I said stuff like that I was completely deluding myself.

You may be being too hard on your profs and TAs. CS departments generally don't cover specific development platforms in their classes because platforms come and go, sometimes in a shockingly short period of time. A good CS department is going to try to educate you in the foundations of CS and software engineering. Stuff that is not in the tech headlines now, but is more likely to still be relevant 10 years from now. Still, it may be that they aren't very good, in which case the solution is not necessarily to drop out, but to find a better department.

That said, if you aren't applying yourself in school, and aren't getting much out of it, then you probably should't be in school. However, if you are not going to be in school, you still have to move forward with your life. You can't just hop on the bus back home and let your parents support you. The accelerator sounds great, but it's a roll of the dice, so you need a backup plan. The obvious choices are joining the military and finding a job. I've never been in the military so I can't advise you about that. If you find a job that pays all your expenses, then your parents may be upset, but they can't really stop you. They probably will be less upset with you if you have a job in hand as you announce that you are leaving school. If you can't find a job that will support you, then that's a pretty critical piece of information, and it means you've either got to suck it up in school or join the military.

My suggestion would be to completely put aside your personal projects for the rest of the year. Focus on your schoolwork, and prove you aren't just blowing smoke, when you say you could excel at it. Prove it. At the end of the school year, start looking for a job. If you find a job that will pay all your living expenses, or if your accelerator works out, then take a leave of absence. If you prosper in your job or startup, great. If it doesn't work out or seems like a dead end you can go back to school. If you really want to pursue your projects as an entrepreneur, then live on Ramen, save every penny, and bankroll yourself for a couple of years.