I am on H1 visa with company A,I applied for Transfer for Company B I got receipt number from Company B. I am working for one client X since 1 month from Company B all of a sudden client gave forced vacation asked me not to come to office until they send me a further notice. Its been 3 weeks passed I didnt get any response from them. I took a client letter from Client X for applying my H1 Transfer, right now my H1 status is pending from Company B.
1)It would take couple of months to get the result of my H1, can I appply for jobs representing Company B?

2)If I change to Client Y from Company B will it be a problem for my on going current H1 process when USCIS goes for back ground check?

3)Can I change to F1 status using paystubs from company B, based on the RFE level for H1B trsfr ?