1. Unless the guy or gal has enough $$$ saving, i would suggest taking an offer from a top 50 with full scholarship.
2. Higher ranking helps but it really boils down to the professor and his network in the industry, and the major...very hard to make a simple verdict. But it makes huge sense for a career back to china.
3. Very bad, don't take other ppl as fool
4. If a phone interview is not scheduled by the school, and the student wants to impress the school admission committee, I would suggest writing an email to book a phone conversation with the intl admission officer or sponsoring professor.
就这些许自己开这办巴。