Birth certificate as an evidence for i485!

I agree. You need to examine the reciprocity table for your country of birth and comply with it.

I got I-140 approved more than 1 year with Employer A. Can I port my PD to Employer B even if employer A revokes my I-140?.

Yes you could be able to retain the priority on these facts.

Once you filed for extension and got the I797, you can pay a visit to USCIS on an infopass appointment and have your passport stamped. With that,...

Do I have to leave the United States in order to do my NVC interview? is there any way I can do the interview here in the U.S.?

How did you enter the United States the last time you did that?

What are the chances of him getting a visa?

He will not be able to get a visa for the very reasons specified by my colleague. He is permanently barred and will have to stay outside of the...

Conditional LPR. How long to wait to petition?

You will have to wait until you are naturalized and then you will be able to petition for yoru parents, not before.

If I take TPS and maintain my F1 status as well, do I need a travel document to travel?

I just answered this question for you in your secod post. read it there.

If a person maintains F1 status while being in TPS, will he require a travel document to travel?

Traveling on TPS is only allowed with an advance parole. International traveling. It is true even with properly maintained f1.

Change of Status H4 to F1 applied at VSC, no response since 6 months. Is it because I transfered from one college to another?

You should have received the answer by now. At least the initial correspondence .

If i abandon AOS may i return to the US??

You might but you also might be hit with immigrant intent allegations at the port of entry.