I would take this advice.
Seriously man. I keep a lot of my HS life somewhat prive, which is why I did not really mention it in my post, but I guess Ill spill some of it here...
I tried to do what you want to do. I dropped out of my HS after my first semester junior year to ride and film. Sure it started my film career, but I could have waited. Plus I did just fine with both school and filming my senior year (altho I got out at 1130 every day).
You DO NOT want to go through what I went through. It is NOT easy. I tried to do the whole online thing as well junior year and I struggled to get two classes done before I got sent away. Ill leave it there, but unless you have a lot of time to do school (which means you wouldnt be working that much, making it kind of pointless), then its not going to work.
Also, I take online film school right now to go along with work and it is VERY stressful and thats coming from someone who mostly works at home (unless I am out on a shoot). I think I spend 70+ hours a week on my computer working.
Go to high school and film on your free time man. A couple of years is not long to wait. What I would suggest over what your thinking is to start taking summer school and an online class or two to go along with your hs classes at school. That way you can finish a semester early and skip your winter senior year and be off with your career.