And every time she did the many, many, many things you listed on your OP.. you did what? just sit there quietly? Then give your DH a telling off every time she left about how unreasonable and horrible his mother is?
I feel a bit sorry for the poor bloke actually, talk about stuck in the middle, he doesn't know any different, he has been raised by this mad woman and loves her unconditionally.. he doesn't feel the same way you do, so will NEVER deal with her in a way that will satisfy you, so if you feel she has insulted YOU to your face, why don't YOU just raise it with her there and then, instead of letting it fester?
I think you are completely unreasonable to expect your DH to set boundaries on your behalf (which you refuse to set yourself).. you've got a voice, use it. If you upset her then so what? You could have dealt with this years ago, you are letting her rule you, you are a bubbling mess of resentment, and you are sacrificing your marriage for it even though you are now NC.
FWIW one thing that stands out is the 'grumps' thing, as soon as she piped up that she wants him to be referred to as something else, I would have completely ignored her, looked him in the eye, laughed and said "of course they will call you grumps, you get to pick your own name grumps!", and every time after that I'd refer to him as 'grumps'.. why you all just sit there and let her control all of you is a completely alien concept, you can't accuse your DH of not standing up to her, while you don't either?!
If you don't do it for yourself you need to teach your child by example that they don't need to take shit from anyone, especially people that are supposed to love and care for them.