i have H1 Visa from company A and worked for 10 months for Company A.
Then i initiated H1 Transfer to COMPANY B and got new I797 + I-94 attached to it(currently working for COMPANY B).

now i want to move back to COMPANY A and COMPANY A told they need to initiate H1 Transfer again.
Meanwhile i need to take a unpaid vacation of 15 days from COMPANY B.
since iam planned for only 15 days vacation do i need to give all of my I-94 while exit??

Do i have any issue while entering US in POE because i have Valid I 797 Of company B and i initiated H1 transfer back to COMPANY A?

can i keep working for COMPANY B after my H1 Transf to company A approved or pending? because i may change my decision later either to stay in company B or move to COMPANY A.