You must be a resident for 90 days for eligibility.

While not common, this should be adhered to if consulate is requesting this.

You may apply for humanitarian parole given your circumstances.

It is best to discuss the options available in a private consultation setting. Good luck!

No this is not necessary if response timely filed and received by USCIS.

Yes that would be a timely response.

Sibling based petitions are very difficult to expedite as you must wait for visa to become available in any case.

Yes submit two photos for petitioner and two photos for beneficiary.

A consultation is best to determine your best options given specific circumstances.

Yes it would be better to file for your son at this time separately given pending N400 case.