No submit only what is requested, which is passport photos.

File it by mail and indicate your occupation by hand on form.

I-485 and I-864 were previously submitted by mail in two different packets because of size. The application was rejected.

You must file with all forms together including the i944.

Not if you were transparent about this in previous applications.

You may file an extension based on the circumstances.

It does not indicate anything other than more information is needed to process your case.

No you would not submit a DOS form to USCIS.

Greatings can i travel to a different state with my valid passport and a h2b visa with exstention.but my exstention is exspired

Yes you may travel out of state with valid ID.

Is it possible for me to obtain Employment Authorization Document if I am being sponsored by my brother?

No not based on the I130 filing alone.

What are the possible scenarios to facilitate the pending case?

Best to consult with an attorney as your question is unclear.