I don't know about under the table merit aid - i wish that some of it existed, but i haven't heard anything about that from current students or alumni who i know. Rodeo, I'm not sure which ivys you are waiting on, but i chose nyu over some of the other big name schools...i just think it's an awesome place to go to medical school. If i were you, I wouldn't feel "obligated" to go anywhere...if you liked nyu more, you'll be much happier there.
The only thing that I wish were better at nyu is the administration. I heard that they screwed up a lot of the mailings for waitlisted/reject people...is that just a rumor? Is anyone thinking about doing the honors program there?