What's the fastest way to be a US citizen? Also, in visa processing stage, can i already go to the US? I have a tourist visa.

You can be hired as an interpreter in Creole or other language for the US military and they can expedite your citizenship. Otherwise, the normal...

You can always send USCIS a letter about your concern.

Uscis

Better to bring a new one if you can.

As permanent resident can my mom petition for her son?

If he is single, yes. He will need to leave the U.S. to get his visa, however, if he entered without inspection.

Can H4 visaholder move to H1B while Green Card application was filed with H4 status

If you are within the six years or eligible for 7th year extension, you can change to H1b when those visas become available. However since you are...

What kind of document I need to submit to CIS when my EB3 priority arrive?

If your I-140 has been approved, you should file form I-485. You will need to prove your job title is the same as your prior job for which you...

Will I have to apply for a green card all over again?

Yes, he would have to file for you again. Better bet would be to get your US citizenship first.

When ordered removed can you just leave on your own? Will this cause an outstanding deportation order?

He should meet with ICE and get papers to verify his departure at the US Embassy in Mexico.

Can h1 B be transferred with 1 month salary slip

Yes.

I took vd can i get married before my 120 days are up and my wife file to keep me here

If you file for reopening and a stay of voluntary departure, it may be possible.