You are right to be concerned. He has been using a Green Card as a visitor visa. I would be prepared for extreme scrutiny next month. He will probably be given the opportunity to surrender his Green Card when he arrives. However, no one can be certain what will happen.
Her case will never get to the interview stage. The case is dead if the petitioner withdrew the I-130. Are you saying she is looking for someone just for immigration benefits?
If you have sent letters to USCIS, NVC, and the consulate before the visa was issued, you have done more than necessary to withdraw a case. I think you can peacefully move on and seek happiness for yourself.
Your personal experience is why you paint such a broad and derogatory picture of half the country's voters? You've been watching too much MSNBC and The View.
Are you trying to file as Married-Filing Jointly? If so, you have to report income for the entire year, but you might be able to exclude some of the foreign income.
I would suggest finding a knowledgeable tax pro for first year filing. Look for someone who knows foreign income, FBAR requirements, and foreign income exclusion.