Hi there,
Below are the answers for your questions:
1. Websites says that 600, but if you have the GMAT range of 600-650 score. Your profile should be extra -ordinary like International player.
2. Should be 700+
3. Yes, you can apply for Manheim business school, Vlerick Business School, University of Cincinnati, Beedie School of Business- Simon Fraser University and so forth..
4. Any B-Schools looks it your overall profile, right from your acads, leadership qualities, managerial role, extra circulars and other.
You may also try B-school selector tool
https://goo.gl/T4Hsgf to gauge your chances for top B-schools.
Regards,
Shoaib