XIAOBAITU, ABOUT 两个EAD卡(以防一个被锯), pls do help!

I have two 485 pending (EB1a and NIW), and both 485s are based on my current job, but I have to leave my current job soon.

It is extremely hard to find a job in my field, and even I find something, most likely it will be a big move (geologically). With a small baby with me, I really don't want to move and leave my hu*****and. Now I found a local job, which has nothing to do with my field and background, but I am willing to take it if I can.

No H1b available this year now. Could I use my EAD (based on one of my 485) to work? Could I apply for another EAD, so if one 485 got failed, I can still use the other one?

And next year, if my new employer want to sponsor my H1b, can they do it for even I already used EAD?

Thank you very much for your help. I don't know whether I am going to overcome all these hardship!