H1 transfer while extension in progress

I am currently working with an Employer A on H1-B Visa on a Perm Full Time position and my H1-B expired on 31st Jan 2018.

My Company A already started H1-B Extension. Currently Extension in progress.

Currently, I am also looking for new job opportunities and if I get a new job, my next Employer B will have to transfer my H1-B to them.

I would like to know ,

  1. Can Employer B transfer H1B on expired H1B with Company A(Extension in Progress).

  2. Just FYI : Cannot convert the extension with COmpmany A into Premium because COmpany A told will not responsd incase of RFE.

  3. If H1 transfer possible, then Is it related to Company A extension in Progress. in other words can it impact the H1B transfer??

  4. If H1B transfer is not possible then what are the option as Company A asking for sepration.

  5. If H1B transfer is not possible, and we will change the status to H4, after 2 months if will get a job then is it possible to change the status from H4 to H1?