Some things I'd like to clarify about international students applying to US colleges.

Here are a list of things that I'd like to make clear (or clearer since sometimes there may not be a definite answer to any of these questions.)

1. Will my application be screened by admissions offices in competition with all applicants (Americans included), just international applicants, or just applicants from my country?
2. Do AP/IB/honors courses actually matter? I come from a school where the idea of honors classes is looked down upon.
3. What kind of extracurricular activities are admissions officers really looking for?
4. I've been hearing that if an applicant comes from a third-world country, it's a big bonus. Is that really the case?
5. Does your choice of major actually affect the decision in any way?

Thanks.