Is it possible to start filing a new LCA amendment while my current H1B Visa extension is in progress?

I am currently working for an Employer 'E1' and a Client 'C1' through them. My H1B Visa Expires 23 Dec and the extension for the same was initiated in Oct and I have the Receipt Notice and the USCIS Case Status is 'Case Was Received'. My last day with the Client 'C1' also is on the same 23 Dec. If I receive an RFE on the extension filed how will my Employer provide supporting documents if i am no longer with the same client?

If I get an RFE while I just left client 'C1', will I be able to initiate an amendment for a different client 'C2'? My I94 Expires Jan 3rd.

During my extension process, can my Employer 'E1' start a new amendment or LCA transfer process for a different Client 'C2' who are located in a different state?

During my extension process, while I am waiting for an approval on my VISA, can I apply for a new job and can my new Employer 'E2' start filing for amendment?