Excellent analysis. Many rules end up hurting those who don’t deserve it, but yet, there must still be rules. It’ll take time for humanity to develop to the point where rules like what you’re describing are less necessary.
I’m sorry for the situation you find yourself in. I am newly divorced, but from the get-go my intention was to keep everything as calm, peaceful and equitable as possible — and thankfully my former spouse agreed. We used mediators instead of lawyers. We decided “custody” (of our younger child, as the older one turned 18 as we were going through this) would be exactly 50/50. Partway through our separation, I suggested we practice “nesting”, where the parents take turns living with the kids so the kids don’t have to move; we continue this practice and will continue it for 2 more years, until the second kid graduates from high school. Neither asked the other for child support or alimony; we agreed to split the children’s expenses — and our respective living expenses — nearly 50/50, with a slight deference to the fact that he makes nearly twice as much as I do (but I have support from my parents, which he does not).
It may sound like we are bending over backwards to put the children’s welfares above our own, and that’s because we are. This split was not their fault and they shouldn’t have to pay any price greater than the one they are already paying by not having an intact, harmonious family.
The least we can do is try to be harmonious in divorce, even though we could not be harmonious in marriage.