Hi,

I also think that you should use this pony for in-hand shows. If you ride him and he doesn't like it, then he will associate people with being ridden, which he obviously does not like! Have you tried contacting any trainers or (i know it may sound a bit OTT) horse whisperers? This could be very costly though , so maybe you could lunge him and show him in- hand during the showing season. And when he is not being used, he could make a great companion. Think of the horse and what he might be feeling.

I hope this has helped you , as i am not sure it will.
Good Luck!