OK, first I want you to understand what procedure has made your husband barred for 5 years. He was put into an expedited removal procedure which does not require a judge. He could have requested a hearing before a judge but he would have sat in jail for months until that was scheduled so he probably waived that right.
Read this link before we go further so you understand what has happened to him.
Second, I don't understand why with 5 pending DUIs he left the US? I understand having one DUI due to medication. You learn don't drive if you take that medicine. But he continued to medicate and drive getting caught 5 times. He endangered the lives of others. Hence the harsh and aggressive treatment and their finding he is a danger to not just himself but to others on the road where he is driving.
He is a guest in the US and yes, the officers did find him mentally ill and dangerous. They don't want him here. He was convicted of violence even against you. I don't want to hear it was your fault. A court heard the facts and found him guilty or he admitted he was guilty.
Immigration does not care about the consequences of him not appearing for the DUI charges. He made a choice to leave the US knowing he faced FIVE counts of DUI. I have never represented a client in all my 35 years of immigration law that had 5 DUIs. Usually people learn after one or two to not drive while medicated. Even if the BAC was a false positive after the first 2 he knew taking the meds and driving leads to being stopped and the BAC reading.
1. I am not able to help him. I am sure there is a lawyer willing to take your $5000-10,000 for a federal court appeal. I gave you the link to finding a lawyer in OC to do that.
2. He would have to apply for Asylum in Mexico. That is where he is now. To apply for asylum in the US you have to do that within 1 year of being here. His persecution happened in 2012 so he had one year after entry to seek asylum here.
3. VD doesn't apply. He already has an order of removal. One has to seek VD before an order is entered.
Would you like me to opt out so another expert can offer you a solution?