Keep defending your children against the grandparents. I also would not let them go to see them alone, or without a responsible adult present. Because something you wrote bothered me:
Now that’s really bad. Who knows what other behaviors are worthy of a wallop, when you are not around. Don’t leave them alone.
Tell the grandparents exactly why you don’t want them around, and what they need to do to be allowed to see them again.
Family unity is bullshit if the family is fucked up, dysfunctional, or family members are cruel, manipulative, and/or dangerous and threatening.
It still baffles me why so many people feel that crazed, evil, fucked-up family members still deserve some sort of “respect”. Respect is earned, not granted as a title. I still am amazed when I go to family reunions, and everybody acts with such “reverence” around my evil, racist, fucked-up grandpa. I am the “black ewe” of the family now because I laid down the law to my grandpa at the last family reunion, and to a couple uncles who tried to jump in to defend him (talk about sock-puppets).
The topic? Oh, there were many choice ones in the past, about how all gays and lesbians should be taken to the middle of the Nevada desert and “nuked”, about how women should receive the death penalty for abortion, about how the “negroes” and “Jews” are taking over the world, etc. But this time it was something far less important when I finally did decide to buck the crowd and stand up. It was simply “he thought it was funny to cut off cats tails” - seriously. Nothing even close to the other fucked-up stuff, or screwing with your kids minds and self-esteem. I dressed him down like a female drill sergeant, and told him he was a sick old bastard. So now my some of my family hates me? Who cares. Sick, racist, homophobes hate me. We should all be so lucky.
Another frequent worry is “ohh…just go along with what they say, after all, you want to inherit something, right?” Bullshit. I got where I am today by myself, and I don’t need any fucking handouts from evil, racist, homophobe family members, thank you.
Oh wait…this thread wasn’t about me, was it? But I just wanted to throw in a couple examples, since others were doing so as well.