Ask for help about question of pending I-485 !!!

I will lost the H1-B job next month. My status: I-140 NIW approval; I-485 pending; EDA approval;PD will probably be current on Aug.
Question:
1.If I could not find a job right after the laid-off, what will happen to my I-485 application. Is there any chance that it will be approved?
2.If I use EDA to work in the same field as petition a few months later,will the gap be accepted by CIS for approve my I-485? What is the maxium time which would be allowed?

Thanks in advance!