Concerning that mysterious AAMC survey--while it might be a "sneaky" way to disqualify you for waiting lists at other schools, I know there were two people in our class that ended up going to other schools after they had attended orientation here (their instate schools). Another one was still on the waiting list at his instate school all the way until Sept 20th (more than 6 weeks into our semester) before he found out he didn't get in there.
So, while it wouldn't be fair to another deserving student, it is theoretically possible to start at one school and then start at another (you will, though, lose half a year's tuition!).
Maple, have no fear! You'll be in soon enough!