H1B Visa Transfer while H1B VISA extension in progress

[sanaullah.md]

Hi,

My current H1B has expired on Oct-2015 , H1B visa extension is in progress and got the RFE.

1)My RFE asks me about the my old project details,but my project was completed couple of weeks back and today(Jan-2016) i got the RFE - How should i respond to RFE, here i cannot get all the documents from my previous project and my previous project SOW was completed Dec-2015.

I have a offer from new employer
1)New employer is ready to do H1B transfer with receipt notice is this safe?
2)Once H1b transfer receipt comes, will it be safe to join the new employer Or do you want me to wait untill the H1B transfer is totally approved then join the new employer?
3)Once my H1B transfer is totally approved then can i join the new employer even if my current H1B extension(with old employer) is in progress.?
4)My H1B extension with RFE is rejected then can i still join the new employer with H1B transfer with receipt notice status?
6)My H1B extension with RFE is rejected then can is till join the new employer with H1B transfer with approved status?

Please guide me

Thanks in advance,
Sana