OP, if it helps at all - and I am really taking the time to do this in order to helpful, not to criticise.
I was the poster who said you sound defensive and these statements are why:
"Veiled insinuations it's us. Unless I'm paranoid."
"I have had a decade of gaslighting saying I'm the cause of the diagnosis"
"I feel its a threat but I don't do threats of socail care, don't imply report me."
"We clearly didn't satisfy there question the first time."
"From my point of view they are hammering it's serious, they suspect its us, yet do nothing."
"Like gaslighting. It's you, but I wouldn't want to prove it's you. I won't stand by my assertion it's you and be counted."
"We don't think they was satisfied with our answer the first time so why not if you don't belive it did they not raise it with higher up?"
"Want to be like other parents that don't have these conversations and are off the sencos radar maybe?"
"If they truly can not be satisfied by me that's there next step and not in my power to prove more that I can, and I'm going to rub them up if I self refer."
I think you need to take as your starting point that the school are trying to help your child and that they are trying to do this collaboratively WITH you.
You've offered no information as to what the veiled threats are, so I'm left feeling that yes, you may well be paranoid given you've stated you could be.
You and the school are on the same team, working towards improving your child's wellbeing. You need to start there, not project past experiences with professionals on to this.
And FWIW I had a meeting with my child's school last week about her multiple panic attacks. I worked together with the school to draw up a plan of action and she's already doing much better now school have put changes in place.
That is how it is supposed to work.