The end result is that now my siblings and I all love both of our parents but none of us respect either of them and we probably never will. If my Dad had put his foot down earlier, a couple of things could have happened. It could have snapped my Mom back to her senses and they could have rebuilt their marriage without the piece of shit pastor tagging along as a third wheel. The marriage could have ended (sooner than it did, of course) and we could have had at least one functional parent who didn't make a shitty choice and alienate us.
My point is that if what your kids are going through is anything like what my siblings and I did, you aren't doing them any favors by preserving the status quo. You may be keeping their two parent home intact but you and your wife are also modeling extremely poor behavior for them. Her for obvious reasons and you because you're showing them that it's best to appease and be walked on when someone who is supposed to love and cherish you is treating you like shit.
I've never met you but I know you deserve better than that and I think your kids probably do too.
In some states you can divorce while still living together; sort of in-house separation. That way you remain united as a family.
If she has so little respect for you its a firm bet that she is planning to leave one day; maybe when the kids are in their teens. so you are just putting off the inevitable.