i140 and H1B extension in process and Moving out of US

[K2016]

Hi 

My i140 (applied on Aug 01 2016) and H1B extension (applied on September 09 2016) petitions are pending for approval and i am moving out of US for 3-6 months to India. Utilized 5 years and 6 months of H1B.

Questions:

1. Would there be any impact to both petitions getting approved. If any how to avoid that.
2. Can i transfer H1B to another employer while in India.
3. How long should i stay with i140 filed employer to retain i140 and not getting revoked and retain PD.
4. Do i need to change to consular processing for i140 petitions and would that lead to additional time for approval. 

Thanks in advance for checking this out and replying back.