I am currently working on H1B for employer A from sep 1 2007. Current visa stamp is until sep 1 2010. A also filed a h1b extension for me. I will soon be having an offer from employer B in 2 weeks. As soon as I have the offer, I plan to quit my job with A and go to India.

1. This is not a transfer since I wont be in status as I quit my job and went to India when B applies. Will this be subject to the cap?
Also transfer/portability rules dont apply here i think, so when can I start working?(oct 1?)
2. I want to come back to US once my h1b with B gets approved with a new stamp but can I come sooner based on receipt notice since my old visa is until sep 1. will I be on status as I am not working with anyone at this point?
3. what if A's extension is processed after B's transfer?