There do seem to be a lot of gotcha's in law about seemingly neutral actions being a legal admission of guilt or relinquishment.

I can't really say how important the legal effects would be as we navigated clear of them. I just relay annecdotal evidence here. But your behavior esp. the effect on the children would be valued by a court no doubt. The legal consequences will most likely differ a lot between jurisdictions.

I think the key insight here is that one cannot infer from rarity of events to them not being regulated in law. Even the rarest kind of human behavior has complex (legal) rules attached to it if it has lasting consequences. Separating seems like an obvious freedom you should have but it is not that easy.

There were legal aspects that did cause a lot of hassle and work I will come to in the pragmatics section.

probably just make another post?

Yes. I will make another post when the next part is written. Took me much longer (11h hours according to my tracking) than I expected given that I had so much material already at hand. But I underestimated the time it took to give it structure and esp. lookup forgotten references (many I couldn't find again).