Lance,
Can you get your mom out of their house and into yours for a few more weeks? As damaging as the psychological abuse is, you need to find out if he's physically or sexually abusing her as well. If you get her out of that environment, you may be able to talk her into filing for divorce. My jw husband was extremely mentally ill and physically abusive, and the elders told me to wait on Jehovah and be a better wife. That's what they tell all battered wives, unless of course, she's the daughter of a higher up. And my husband was threatening to kill me. Yes, doctors and judges saw fit to forcibly commit him to a mental hospital twice, but the elders just couldn't understand why I wanted a divorce and to be as far away from him as possible.
Your mom has nothing to lose by filing for divorce. Because she was in a long term marriage, he will have to pay her spousal support and split his retirement with her. She can get a divorce but of course can't remarry until she proves adultery on his part. But who knows, if she gets rid of him, she may want to get rid of the cult as well. Please get her out of that situation. If she needs to talk to someone who was abused by a jw husband, have her call me, or I'll call her if she/you don't have unlimited long distance.
Please, Lance, as upset as you are, YOU HAVE NO IDEA WHAT IT IS LIKE TO BE ABUSED LIKE SHE IS BEING ABUSED. It is absolute torture to be a prisoner in your own home and to fear the man who is supposed to love you. If he is crazy enough to act like he's acting, he's crazy enough to hit her or worse. And he knows that he'll get away with it within the congregation.
Will try to pm you my phone number.