So the gelding is still *green* but calmer now that I've had my nutritionist come out and change his feed. The guy at Tractor Supply was the one who suggested the Purina Active Pleasure (which the nutritionist, as well as someone on here, said was a bad idea), and I don't know jack diddly about feed, so I took your all's advice and sure enough, a low-starch low-sugar feed made him calmer. At least now when he bolts, he doesn't go with as big of a hitch in his giddy-up. ;] No doubt the fact his owners were feeding him a feed that was for thoroughbred racehorses was a factor..
His owners have decided it is their obligation to keep him until he is "ready for the world" and I respect them greatly for it. They said even if they can't use him for what they want, they will make sure whoever gets him will understand how he is, and will not run into the same problems they did. They're planning on putting a year of training into him to make him a show horse, or whatever ends up being his niche. They don't want him ending up in a kill pen, or in the wrong hands. Good people!
I also have pictures of the saddle at a better angle from yesterday, to show it isn't rubbing his withers. Just gotta get on my other cpu and upload them (I'm on someone else's laptop right now).