I 140 approved 485 pending for more than 180 days from company “A”, I have EAD and AC21 done with company B. I have a current 7th year H1B from company B.
Got laid off due to lack of work. On my request they are holding my last check. I am feverishly looking for job and hope to get land soon.
As soon as I land a job I will be working with EAD and doing an AC21.

1. Do I ask company B to give me my last check and withdraw H1 B? this will prevent any spot checks by INS officers.
2. Do they check tax returns from previous years during a 485 interview
3. How long do I have to land a job?
4. If something goes wrong in 485, Is it possible to file an appeal and meanwhile turn in another I 140 in your 8th year of H1 B extension.