Your school has its own college rep at the admissions office who is aware of all the things you mention. College admissions offices look at Grade distribution: that is, they see how many students get As, A-s, Bs, and so forth, in a particular course. For example if the highest grade in BC Calculus is a B+, then you’ve done really well if you got a B+. But if the best grade was an A, the B+ doesn’t look good no matter how hard you study. By the same token, if most of the class gets an A then your own A (if you get one) won’t have as great an impact as if you were only one of a few students who earned an A.
If you have perfect Board scores and you score “5” on your AP exam the person in the admissions office assigned to your school will know the circumstances and grading system at your school.