Anyway, I don't want to impose a diagnosis on anyone, I'm just trying to figure out how to stabilize the family relationships. I can honestly say, the chances of him going to therapy are virtually nil.

A. Borderlines are borderlines. They exhibit characteristic borderline behaviors pretty much all the time. That said, they are not always hateful. Like asthma, the illness is always there, just really bad sometimes versus other times. People in the family "get use" to the behaviors (walking on egg shells), and may even be blinded by the behaviors. We tend to make excuses for family members. Our children only know us as parents, and are taught to live our way. A good read on this is Understanding the Borderline Mother by Christine Ann Lawson. I know yours is a male figure, but you get a good feel from the book of how the various borderline thinking mechanisms work. Likewise, you get a good idea of what might be a better behavior on your part.

Clearly borderlines act differently. In this case, if you are liked, you are treated differently by him than if you are hated. Ultimately, you need to do the right thing for yourself. Compromising your own ethics or value system will not help you, and certainly will not help him. Borderlines (there are multiple types) look at the world differently. In this case, he sounds unwilling to even consider alternatives or make any compromises. Any compromises you make will not be reciprocated in this case