OTOH, boundaries are necessary. Walking away from angry conversations is a great one. I'm a little more mixed on the discipline ones. It's important for kids not to be able to play parents off each other. Consistency in discipline. Before our D2 was born W and I agreed that we'd back each other on discipline always. If we didn't agree we'd discuss it privately, but not contradict each other in front of the kid/s/. And it's the one area where I still do seek her out to discuss things, even if I avoid R talks like the plague these days.
To me your child-related boundaries sound almost like preparation for D and separate parenting. Dealing with your kids is the one area where, even post-D, there needs to be communication, consistency, and common ground. Where you're at now, it's also a chance to connect in a way with your W without initiating a conversation. So I always back my W up when she puts D2 in time out, because generally D2 fully earned the time out, and because it's still important for kids to see a unified face on these things. Just my 2 cents.
I should have provided a more specific example on the discipline item.
For instance, D5 has been acting out lately. My W may ask her to do something, and she starts to throw a tantrum, so my W will tell her to go to timeout (we typically have our kids sit in a calm place, legs crossed, hands folded, count slowly and breathe in and out). Maybe D5 will be defiant, maybe call my W a name. In the past I would step in and maybe say "Don't talk to your mother like that" and then start trying to help get her to go to timeout. My point now is that if my W is in the middle of handling it, I should not step in. I can back her up, but I should not jump in and try to "help." And vice versa. My W does step in sometimes when I feel like I calmly handling something, so as a boundary I think I could just tell her "Thank you for offering to help, I will handle S/D right now". It can be frustrating because kids sniff this out and start splitting the parents.
