Check the link above. It provides: File Form I-129F at the USCIS Dallas lockbox. U.S. Postal Service (USPS): USCIS Attn: I-129F P.O. Box...

You need to provide proof that your husband is currenlty on valid L-1.

You cannot work with work authorization.

File I-539 to extend their B-1/B-2 status.

Asylees are authorized to work incident to their status

H-1B and H-4 visa holders can travel overseas while their green card applications are pending because they are dual intent visas.

Yes they can ask for information they need to adjudicate your case even if it was not initially on Form I-485.

Your wife needs to be a U.S. citizen to sponsor her mother.

You can call USCIS to check. Also, if you want another copy of your I-140 approval notice, you might want to file Form I-824. Or check with...

You can do change of status inside the U.S.