I'm like you, I'd rather get hit between the eyes with the facts and decide upon a plan of action. I don't understand Bube's inaction either and it's very frustrating.
If I saw my mother hitting my younger sister, I'd stop her. This whole family is afraid of this woman. That alone says it all.
Bube, only you can stop this insanity. What has to happen to make you end it? Seriously. I'm afraid that when your D's actually are on their own, they won't want anything to do with either of you.
Like Cobra, I'm sorry if this sounds harsh, but having been in your girls position, my heart breaks for them. And for you. You deserve to be happy and have some peace in your life. I don't know how you have the energy or heart to go to work everyday and come home and referee your W and girls.
What would happen if you just sit your wife down while the girls are gone and tell her that until she can change her behavior (long term), she has to leave within the next week? Why are you afraid of her being gone?