Perhaps I could offer a couple of points here:
Firstly, the issue of what type of aircraft the ATC should operate is a secondary one as long as the RAF and the MoD continue to struggle to operate within their own rules. Wood, fabric, glass or metal, as long as they can't fly civilian schoolchildren within the regulations and standards set by the MAA they are going to go out of business.
Remember that the development of the MAA and the preparation of MAA regs have been closely controlled by RAF senior officers. The MAA regs, and this has been a constant refrain, don't impose new requirements as far as basic airworthiness management goes. Any competent procurement or maintenance organisation can meet them, albeit with a heavier management overhead. The RAF aren't 'slaves' to the MAA or the regs. The key issue is whether the RAF and the MoD are actually 'competent' to manage airworthiness.
If they're not (and I'd suggest that the evidence is stacking up that in at least some areas they aren't) that's a bit of an issue. Not only for the schoolchildren being taken up into the sky, but for anyone operating RAF aircraft.
As a former Air Cadet, who was and remains eternally grateful for the opportunities and training the ATC gave me, I would add that (in my view at least) the ATC is primarily a recruiting tool for the RAF - that's why the RAF spends scarce taxpayers' monies on it. Yes, there are all sorts of excellent benefits for the cadets, not least in developing valuable life skills, but the core reason for the ATC's existence is to encourage young people to think about a career in the RAF. That's not a bad thing - I think young people should consider careers in the RAF. I just wonder whether the monies being chucked by the RAF at the ATC to dig it out of the hole it got into represents a good return on investment.
Not to mention the reputational risk of flying kids around in non-airworthy aircraft.
Best regards as ever to all those doing the valuable work with the kids,
Engines