Finally got round to reading the thread back, just, but have instantly forgotten most of what I've read.
Sorry, I really get cross with my swiss-cheese brain sometimes. 
THC, I hope ds is ok and hasn't had anymore scary episodes. You always sound so calm and in control, you're one helluva Mum. 
Ds2 had his second physio appointment today. Feedback from the hypermobility bod was that it would be a tough fight to get him properly dx'd, despite meeting the criteria, but that it's up to us if we want to take it on. (No advice on how to pursue it if we do though.
) Physio felt it would be a fruitless fight, as he wouldn't be offered any more than the physio he's already referred for anyway.

I explained that whilst obviously the most important thing to me is to reduce his pain and improve his mobility, I felt that, knowing them, the school might not take things seriously enough without a proper dx. We discussed sensible precautions and actions the school should take and were in agreement about them. Then she suggested I ask the GP to write the school a letter, which is probably pointless, given that they've received the cons paed dx of 'lax ligaments'. The physio actually refers to him herself as having jhs, so I was a bit
that she won't do a letter herself.
I asked her to check his feet to see how flat and overpronated they were and she said that surprisingly they're not too bad at all. She asked to see mine to compare and said his are nothing like as bad and she reckons we can improve them enough with exercise, rather than orthotics, as whilst I have no arch at all and a severe inward roll, he actually has a decent arch (so at least the paed got something right).
What she wants to focus on now is building up his strength and stabilising the joints to reduce his pain. We worked out a circuit of 12 exercises for him to do daily. He has to do each exercise twice, so roughly a 24 minute circuit. We start tomorrow and are back to see her again next week.
She also spent about 15 minutes trying to persuade me to buy a Wii.
I explained that we can't have one, as ds1 has autism and is obsessed with computer games consoles, so it would be a source of constant arguments and dischord, but she was very insistent, saying it would be the best thing for ds2 in terms of indoor exercise. I'm not too impressed by that really, as it seemed a bit like, if they recommend the Wii fitness stuff, then it makes their job a lot easier, as they don't actually have to come up with an exercise plan themselves. 
One of the good things is that the elements of my circuit training dvds that ds likes to do are ones that will, with a bit of adapting, work well for him. So that might actually encourage me to start exercising again and if I'm doing it with him, I won't be able to do my usual and push myself too hard, I'll have to ease into it very slowly.
Still ruminating on the appointment really. Feel a bit fobbed off, as basically we've just been told to improve ds's fitness and he will be fine. I kept explaining that the reason he hates sport is because he always ends up either injured or in pain and she just said that once he's fit that won't happen anymore. No advice for how to get him fit when he is in pain almost as soon as he starts to exercise (or in fact just by sitting or moving wrong). She just said to work out his tolerance and then go only half way there rather than pushing to his limits. That doesn't really help, as he can be in agony having just got up from a chair - how am I supposed to make him exercise then?
No advice on what to do when his joints give out during exercise either. Surely we will have to stop as soon as his legs start to hurt (which is what she advised for PE at school) which kind of renders the whole thing impossible. 