Hi Chooch91,
Don’t stress, you haven’t left too late as your case number won’t be current until 2022 anyway!
1. Best endeavours should be ok. I also did approx dates on terms for education. Addresses, I’d try to be as accurate as possible if you can get it to the correct month.
2. Check the AU reciprocate page, this specifies exactly which AFP check you need to get. They will post it to you. I would suggest ordering this ASAP as there was a big backlog for a while there, mine took over a month.
3. Last five years of travel by country only, only dates required for USA travel
As for new address, if this is the only thing stopping you then you should totally submit the form now, as it is correct at time of submission and moving in the same city won’t affect any other background checks etc they need to do.