@noblegiraffe My educational experience extends to having been to school and having a DD who is at school so, professionally, I don't know sh*t from sugar. If I'm reading you correctly, you are working in an environment where the central guidance is next to useless, the SLT make it up as they go along but blame working teachers for any blow-back, a pastoral team that is unqualified to perform its role, and the complete absence of a legal framework for making or documenting decisions.
I could hug you. While it might be easy to criticise any individual decision that you made, it's clear that you are trying to balance competing needs and wants while working in a miasma of gloop.
I would have walked in a New York minute.