EB1 GC

[Rahul7]

My EB1- C  i-140  from my current employer is approved on March - 2018.  I completed my GC interview in July-2018. I'm currently on EAD ( valid till 2021).

Its now about 2 years since my i-140 is approved and around 1.5 years  since my i-485 was filed. It was file under L1A category by my employer.

I received a new job offer (same managerial position) from a new employer. Now,

1. To Join the new company, should i file a new i-140? or the existing approved i-140 is good?

2. Can my Employer A revoke my approved i-140?

3. Will my priority date change due to this switch?

4. Any other document should i file for accepting my new job with the new employer B?

5. Will there be any impact on my current GC process?

Thanks