HI I'm on ODSP, and yep that's the acronym.

1. I was accepted the first time. I actually wandered into their office and since I have a wheelchair it's a lot more obvious that I AM disabled, thus really qualify for the program.
2. My doc filled it out in maybe 20-ish minutes as I recall.
3. I can't remember unfortunately, but not long at all.

I applied for it back when I was 18 I think too. (It's been a while can't remember exactly how old I was). It is a bit weird, but it's free money and it comes with a drug plan which is AWESOME if you're on different meds that are expensive. You dont have to be on it forever, just use it as long as you need it. They also have a job help associated with it (Ontario Works) which can help you find a job even with a disability, if you're looking for that sort of thing.

They are finicky about financial stuff, so make sure you've collected bank statements when that part of the process is in play. The people are pretty nice, and I do like their office. It's a lot of paperwork, but if you've got a disability (a physical one especially) you're quite likely to not get turned down at all.

If you've got any other questions, send me a PM and I can help. Even for emotional support.