And it absolutely does boil down to good food, routine vet care and prompt medical attention. Okay I'll admit providing a safe living environment and starting off with animals that were bred for soundness and to be free of genetic defects also factors in. But love alone hardly extends their lives. If that were the case we wouldn't see hoarders with scores of dead animals.
There is a lovely lady in my chapter of a certain horseman's association who's son used to be a big lick trainer, working for a decent-sized barn in TN that has turned out some champions. He took a shine to me and we dated briefly a few years ago after he had a change of heart and moved back up her to Ohio. He had a lot to say about the politics and goings-on, especially regarding the absentee owners who just let the trainers and farriers make all the decisions.
I believe his exact words were they believed what they wanted to believe. They'd ask the right questions "You don't do *that* kind of training, do you?" and they'd just smile and say "oh of course not!". He also told me he came the opinion rather quickly that these people were either too caught up in seeing their horse win to allow themselves to see the truth, or were just plain stupid. He said it was obvious to anyone who spent even a little time watching the goings-on at the barn the horses were being sored.
Like you, (according to him) not a one of them could tell you specifics about how their horse was shod, trained etc. They just let the trainers and farriers "do what worked". In part it's that kind of passive horse ownership that allows, in this discipline, the crap to continue.
I do hope for your horse's sake your trainer is on the up-and-up. But I'm not going to lie...I think it's pretty foolish to show such blind trust with any trainer especially in the TWH performance industry.
And P.S...This fella never got any tickets in the few years he trained/showed. They don't all get caught. Please don't try to counteract my argument with "no tickets, ever!", you'll have to come up with something better than that.