Please Help On Rfe H1B

[WhatToDoDude1]

Hi,

Need your help. Please suggest.

Currently I am working for company A. I got an offer from company B and they have filed the H1 transfer.
But there is an RFE, which they are working on.
But company B wants me to join them and says it might get approved.
Though I want to Join B, I am in doubt to put resignation to current company A.

Meanwhile, I got another offers from company C and D. They want to file H1B transfer.
Here I like to Join to company B than the others.

Now my two questions are here.

1. For filing the H1B transfer for company C and D, should I inform them about company B's H1b situation or do I need to send them the company B's receipt number? I was about to send only company A H1B notice.

2. For an instance, If I join company B and after few days, company C or D H1B got approved and company B's H1B is rejected, then I switch from Company B to C/D? Will I be still in Status and Legal.
Because, I would have signed the I9 form with company B.

Thanks.