When can I apply for my wife USA citizenship? When can my wife apply for her mom, dad and brother who is 19 yrs unmarried?

She may apply 2 years and 9 months from date of GC issuance.

Yes you should indicate any other names used and provide proof of legal name change.

Do I have to pay the biometric fees for both I-485 and I-131 forms or just one?

You would pay the one time biometric fee and not pay again for the I131 fee if filed with I485.

Immigration question?

You may travel to Nigeria, marry and apply for your spouse through consular processing.

Insufficient evidence or missing documents are common reasons.

Yes you may do so and should update your address with any relocation.

Yes this will impact the sponsorship so you should seek to obtain evidence of sufficient assets.

This question does not apply as beneficiary is outside of the US.

What if citizen spouse reports to immigration that we are not living together what would happen to me like will they deport me ?

It may be worthwhile to have a consultation with an attorney for review of your marital history to determine alternative options.

Petitioning for family members ?

Yes you may file for the I130 for your sibling and children. Whether they are adjustment eligible requires consult.