Pls Help: H-1B & EAD questions

My hu*****and and I are both H-1B holders, and in the meantime, I-485 pending. (He is the primary applicant.)I submitted an application for H-1B extension in mid October, and am still waiting for INS approval. Can I apply for EAD now? Will that affect my H-1B extension?

A lawyer represented us when we filed I-485. Does that mean we have to apply EAD through him? Can we do it by ourselves? What should we pay attention to?

If I lost my job before I got INS approval, what status would I be in? Shall I apply for H-4 in that case?

Thank you all for your kind help!