[stevewoods]

Hey!
1. For PhD there is nothing like min. GRE or TOEFL scores. It depends upon the university. Usually GRE score above 315 and TOEFL above 100 is considered decent.
For MS, these scores matter more so GRE above 320 and TOEFL above 110 is preferred.

2. For PhD, recommendations from well known professors or researchers (having PhD and Publications) is most important along with your research experience. Ideally if you have a publication in a decent forum then it gives you an edge over the other applicants.
For MS, research experience is not that much needed. The scores, CGPA etc. become important parameters for your selection.

3. During visa interview you are required to show how will you support your studies in USA (at-least for first year in case of PhD and for 2 years in case of MS). Generally all good universities provide funding in the form of RAship or TAship to all their PhD students so there is no need to show any Bank Balance during visa interview if you are going as a PhD student.
In case of MS you will have to show that liquid cash and assets to prove that you can support your studies.