个人意见,仅供参考:
1. I think after your 485 has been pending for 180days, your previous employer can't revoke your I-140 even they laid you off.
2. Most likely USCIS will approve this H1B transfer.
3. I don't think the gap is a problem. You didn't illegally work at all. Even your new H-1B is denied, you can still work with EAD card.
如果我哪里说错了,请大侠们指正。