L1B to L1A conversion - 5 yr max out in 4 week. Stay legal?

USA L1, L2 Visa
1

My current l1b petition is expiring on 27-sep-14. My employer has decided to file for L1B to L1A conversion early nex week in premium processing.
Here are my questions -

  1. Does L1A need to be approved at least 6 month prior to maxout period or it is recommended to have it approved?

  2. In case we get RFE then is it legal to stay and wait for result?

  3. In case we get denial, then what are my options to return to US ASAP?

i will appreciate if someone can answer my questions.