You may leave that question blank or N/A.

You may leave this blank or N/A. Either is sufficient.

Yes you may withdraw the I485 when responding.

Questionable whether she would be approved.

Yes these petitions may be scrutinized. Best to find a FOIA of the immigration records.

Yes you may request expedited processing with USCIS.

Yes this is possible but whether approved is questionable.

It indicates that the case is still pending.

You should reside in the state which you are applying from for at least 3 months prior to application.

Yes this will delay the application but likely not significantly.