H1B approved and applying for L1B extension

[ramana21]

I am currently on L1 with Employer1. I have applied for H1B thru Employer2 and got a petition approved. Received an I94 which is active from Oct 1^st. I have now applied for L1Ext thru Employer1. My L1B visa expired and I am on the receipt number received for L1B ext.

 

1. What are the potential issues I will face considering a specialized knowledge argument with one company and performing a specialty occupation with another company?
2. Will applying for L1 B extension affect the H1B petition already approved by USCIS?
3. If I get L1B ext approved will I be able to work beyond Oct 1st on L1B and change job whenever I find a job on H1B?

 Please advice