Magical

Make sure he keeps his domicile in USA or you guys will be having issues like me

What visa are you applying for?
You should get an RFE with all the documents requested.
Everything should be send in the name of the petitioner. Just write a letter to USCIS saying that the requested documents are attached and include the case number.

You can always state both the petitioner's and beneficiary's names. Also state the receipt/case number as well as the A-number. That way the embassy can easily identify which petition it belongs to. If it involves the USCIS, you should be attaching the RFE letter.

So, you obviously went thru NVC process and embassy wants further documentation
Yes, send it with current embassy # on top right hand corner with both names (petiioner first) and DOB's 
also, send papers at the same time so they are kept together
if you received a paper telling you what they needed there is probably also a cover sheet that needs to be sent in with all documents
Good luck

The green card arrives through the mail. You do not need to be present at your home or sign anything. If you move and have your mail forwarded to your new address through the post-office, you should not have any problems. But if you were to move before you receive your green card, it is important to inform USCIS of your new address.