applying and studying at university

Okay, as I understood, I don’t really need SAT subjects for applying to Harvard university, but if I show them, it will be beneficial for me. Someone said me the more I will have SAT subjects, the more I will have chances to pass different departments of Harvard university. Is it true?

But also, I want to apply to Harvard university as first year student not as transfer student.

Can 2 or 3 of my personal teachers, who are neither my school teachers nor university teachers, and who know English very well write recommendations?