L1 with employer A and H1 with employer B at same time

I do have my L1 Visa with employer A and am currently in India. Employer B filed H1B (visa to be issued abroad) for this fiscal year and the petition is still under review with USCIS. Could you please answer the below questions.

(1) Can I travel to U.S with employer A on L1. Is there be any issue for my L1 when H1B work permit got approved.

(2) Is there any way that I can start work with employer B without stamping If I go to US on L1 with employer A

(3) While an in India, If I got my H1B WP approved.. and stamping is also through. Does my L1 be still valid?