First talk to the prospective employers immigration attorney. They will need to initiate a new petition.

Can I file my I-140 when I can see my country of citizenship is not correct in certified PERM?

Please talk to the employers immigration attorney.

Apply for sister in 98 can a sponsor skip the affidavit of support paperwork if it does not have a job?

You need an affidavit of support. You can get a joint sponsor or 2 sponsors. You can also base the affidavit of support based on assets or on...

Can I be protected in some way if the decide to fire me?

I would talk to an employment law attorney to find out if you are eligible for any relief and I would also talk to an immigration attorney to see...

Premium processing

Each petition will require a separate PP fee.

What document do I need to submit with my form I-765? What would be my eligibility category for EAD, (c)(19) or (a)(12) ?

see also http://www.uscis.gov/humanitarian/temporary-protected-status

Make and info pass appointment and have your passport stamped prior to departure.

Admitted on ESTA waiver instead of valid tourist visa. How to extend the stay?

On ESTA while in the US, you cannot change status. She can leave and reenter with a visitors visa.

3) what is the processing time for a h1b extension in regular filing?

Talk to company b's lawyers for 1. Talk to company a's lawyers for 2. They know your situation the best.

1-148, spouse surname (additional letter) and in passport (no additional letter)

The name/spelling in the passport controls. You should be ok.