Hi Lori,
I found this site accidentally (when I googled dyspraxia with Interactive Metronome which I'm looking at for my son) and just felt I had to chime in. My son is not gifted but does have dyspraxia and I have spent years looking for information and ways to help him and reading what you've said above I have a couple of suggestions. It's definitely not too late and there's lots of things you can do everyday that will make a difference.
First I want to ask if he's ever been checked for retained infant reflexes? One in particular - the ATNR - can make handwriting extremely difficult. If he's not been checked you can do this easily yourself. Google ATNR and you'll find Youtube clips showing how to do it and then there are exercises that will help integrate the reflex. Think of a baby lying on its back that turns it head to one side. That arm will automatically extend and the opposite arm will flex. If this reflex is retained it can make it very difficult for the child to write because once it passes the midpoint and the head starts turning the arm will want to go with it.
I also found my son didn't get dizzy. The vestibular system was not receiving messages properly. As well as OT exercises to stimulate the vestibular system (the PT will cover this) I took every opportunity to encourage him to swing, jump on the trampoline, spin on merry-go-rounds or just around the room. He loved it because he was craving the stimulation. The day he got carsick for the first time I knew we had made a real breakthrough! Best of all, after years of standing on the sidelines he can now play soccer with his friends. He used to fall over when he tried to kick the ball and the game was just to chaotic for him to cope with.
You mention the feet and pain in the legs. I resisted for a long time taking ds to a chiropracter but I regret that now. Some chiropracters controversially claim to help with dyslexia and dyspraxia so there is a lot of negative literature out there. DS was unable to stand with both feet facing forward and I noticed that he generally had all the weight on one foot. When he started requesting us to stretch him I finally gave in and took him. He had gotten into bad habits because of his poor balance (e.g. standing with his feet pointing outward) that had actually knocked his back out of alignment. I could see that one hip was higher than another when I was shown. He's much more comfortable now and he's working on his posture. Not easy for a child with dyspraxia because of the low muscle tone.
It doesn't sound from a quick scan above that your son has trouble reading - but do check that he has reading stamina. That is something that does need to be fixed while they're young. If you find a problem you'll need a behavioural optometrist or someone who can give him vision therapy. The eyes are controlled by muscles so it makes sense that there will be issues in that area when a child has dyspraxia. I'm very cross that I had to find that out for myself.
Unlike dyslexia where there is loads of research (and funding!) dyspraxia is definitely much lower profile. Because dyspraxics can read it doesn't seem to matter as much to educators but it does hamper them in myriad ways.
I'll try and drop into this site again in a week or two in case you have any questions and good luck.
