Any Risk in H1B Transfer in 6th year & Immediate GC Filing

[[email protected]]

I am currently in company A and am in 6th year of H1B and my visa(&i-94) expiring in 1-Jan-18*and i have I-140 approved 1.5 year before. I got*another offer with nice package to join Company B and they are willing to do H1B transfer and immediate GC processing. My extension is still not filed with company A. Company B is looking to join in 2 weeks period using H1B Transfer Receipt number and they are not agreeing to wait till i get my extension. Below are my questions,

1. *If i join with H1B Receipt number, any risk involved in 6th year?*
2. Will i get 3 year extension if i do H1-B transfer using the I-140 from Company A?

3. If H1B Transfer is approved with Comp B, then should i do H1B extension immediately after joining before 1-Jan-18?

4. If i get 1 year H1B transfer, then should i file PERM *& I-140 again with Company B within 1 year of visa validity?*

5. Can the company A possible to revoke my I-140(got 1.5 year before) and will there be any chance of H1-B Transfer denial*?

6. Final question, is there any other risk involved with my case?*

7. If Company B is not willing to wait till i get my H1-B transfer with Company A, then should i reject the offer?

I am confused on whether to accept the offer or to stick with Company A and appreciate any suggestions.*