natalie, I have not read the whole thread, but the idea of all teachers being first aid trained is a non starter.
For a start, a first aid situation requires someone with unlimited time to concentrate on the injured or sick child, this is not remotely possible for teachers.
First aid situations happen repeatedly throughout the day, and cause massive disruption to designated first aiders, they can only realistically be staff who's tasks can be stopped and started randomly.
The insurance required to be a first aider is prohibitive. The unions discourage teachers admitting if they have first aid training, and you may actually lose your union support if you are personally advised not to, and do so anyway.
I never ever ever give first aid to a child at school. I don't even make any sort of judgement about whether first aid is required or not, or if the child is faking or not. I just send to a first aider/ call a first aider and they make all the judgements. they are paid extra to do so. Meanwhile, I continue teaching the other 29 children.
These days, you need two people, one as a witness, before you physically touch a child. It requires checking paperwork before you start, and completing much paperwork when you have finished. It is a complex and expensive situation, nothing like simply treating your own children at home.
Having said that, I am first aid trained. I would never officially admit that to the school, or act in any non life threatening situation. Of course, in a life threatening situation, I would, and have taken action, and dealt with the legal and administrative complications after.