Sure it's a legitimate question. I'm a homeschooler and am not sure exactly what proportion of highschoolers take calculus. It does seem though from reading about AP calculus that is much more common than when my parents were in school.
It's definitely a crappy strategy for getting into a "good" school because all I've taken are math and science courses from the local college.My parents tell me I'm too narrow minded. I can't stand humanities or english.
What do you mean by quality? I have tried to prove or at least understand the proofs of the various theorems. I think I have a good conceptual grasp of most of the material if that's what you mean. As for reading on my own, I tend to get too wrapped up in what we're studying in class to work on something else at the same depth. It seems I'm always obsessing about some little detail in one of the proofs.