But you are very rude about supply teachers and those who choose to stay in the profession.
Also, what does 'scum of the earth' mean for you? Do you mean that you are treated like 'dirt'? Or do you think that there are people in society who are, to use the hackneyed and vile cliche, 'scum' and you don't want to be categorised with them?
What is your 'subject shortage' and how can children benefit from it? I understand what 'skill set' and 'experience' are, in relation to your valued attributes, but what is the other?
It isn't 'terrible' pay, surely? It may not equate to some salaries, but it's better than some other salaries.
I don't think it helps the cause of teachers to exaggerate all the grievances, and use lots of inflammatory terms, like 'scum of the earth' and ' absolutely hound me'. It doesn't help non-teachers to understand what you are meaning. It's obvious to most people that you must have a relatively nice quality of life, if you are not working for thirteen weeks of the year and able to spend holiday time with your own kids, to travel and to recover from the stress of working. That is a great perk. That is better than many employees experience. It's just so obvious that this is a major advantage of the employment. Any work you need doing on the house, or visits to relatives can be comfortably fitted in within school holidays. Why make out every aspect of teaching is hellish?
Behaviour in the classroom is a major problem for teachers - and money for resources. But a parent pointing out grammatical errors isn't.
If a solicitor spelt your name wrongly on a conveyancing exchange document, or sent an email to you, meant for somebody else ( common mistakes I've known to be made) then they'd apologise and reassure about confidentiality. The whole reason professionals earn a lot is that they hold themselves to standards. Standards which suggest deeper layers of expertise and understanding. It's ok for teachers to make typos and loss of concentration mistakes, but not so great to say that these don't matter and parents are embarrassing themselves by pointing them out.
TAs earn less than teachers and often do a lot of explaining the tasks to kids and managing behaviour. The distinction between teachers and assistant teachers is that the trained ones are supposed to have some greater academic training and appreciation of rights and equality discourse. Using scathing language about supply teachers and those who stay in the profession doesn't suggest an understanding of how to, and how not to, speak about people.