I cannot answer many of your questions, but I do know that if you wait until your 18th birthday to take the GED it is super easy. That is what I did and then I was able to take courses at the community college very easily. I never studied for the test and was able to pass it with no trouble and passed the entrance tests to college, not bad for a 10th grade drop out, so with your strong academics you should have absolutely no trouble.
I know that many of the umbrella schools for home schooling offer diplomas and are accredited. I do not know if they will take someone in who is so close to graduating.
Have you checked into the Florida Virtual school system? Perhaps you can finish up your credits that way, and still qualify for a regular High School diploma?
www.flvs.net
It is completely free.