CAn someone please clarify the standards to meet licensure requirements for me?

I hope to practice medicine in NY, and as it stands, only the Big 3 schools, along with Saba and SMU are approved for NY.

HOwever, if I attend a school that is NOT approved for NY, will I still be able to gain licensure in that state by other means???

Secondly, if I start my education at a school not approved for NY, let's say St. Martinus, and in the middle of my basic sciences, the school is approved, then I should have no problem obtaining licensure in the future???

I'm not too sure how this all works. Some say the school needs to be approved prior to taking ANY courses. Others say the courses taken will be sufficient, even if they were taken prior to getting approval.