Let me seeeeeee....
1. Many top schools (i.e. Harvard) say deferred admission is considered on a case by case basis. Would my startup succeeding be a strong case for deferral?
Best would be to speak with each school about this. In my experience, almost all the deferrals I know about where given for personal and not professional reasons, so I'm not sure that "my startup succeeding" would be a good reason, although maybe if you have some huge one-time thing (like an IPO, or a huge deal or something) which will be over within a year, then maybe.
2. Up until what approximate date would I be able to put in a request for deferral with a decent possibility of it being granted?
Better contact the school on this one.
3. What top MBA programs allow you to defer your admission?
Well, that's a good question, but again, speak witht he school. It's better not to apply with the idea in your head that you will be able to defer anyhow after because it doesn't always work.
4. If accepted to an MBA program, what will be my appx. decision deadline on whether or not to attend?
This is on a school by school basis. They will give you a deadline, based on the Round you applied in, and you will be expected to give in your answer before the next round is considered.
5. At what point does your age start making it less likely you'd be admitted to a top MBA program?
In the US, let's say 31, and Europe 33... But this is approximate.
6. What schools will waive application fees for low-income prospective students?
Lots. Again, this is case-by-case.
7. What schools offer the possibility of full-tuition scholarship/fellowship?
Most, if not all. But you have to be good enough that they should want to offer you this wonderful rarity.
8. How much will I hurt my chances of being accepted to a top MBA program if I take the next two years off to backpack the world? (My profile is provided below)
It will hurt your chances. Better would be to get in R1, and then take the next 8 months to backpack...
Hope this helps!
If you like the post, give it a KUDOS!