This unfortunately can happen so try not to worry and wait rescheduling.

It is possible through good faith marriage and waiver depending on nature of case.

Await scheduling of the appointment before attempting walk-in.

More information is needed about the criminal incident. Best to consult with an attorney for guidance.

You will need valid proof of ID for marriage license purposes.

You may inform the officer at start of interview.

You can file a replacement through form I90.

Yes this is possible given the material misrepresentation.

Contact NVC to inquire about case details once priority date is current.

You may attempt entry but could be denied given pending PR petition.