I just noticed this thread. We have been emailing about the snake and the show, but didn't realize you posted it here, and that you sent a letter to the promoter.
The letter is a good idea. An even better idea, DURING the show, is to write down any complaints with the vendor name, and discuss it with the promoter right at the show. Then the promoter can actually go and see for himself.
One person complaining will help a little, especially if it is something obvious, like dead animals, or almost dead animals. But several people complaining about the exact same thing will help more.
I was less concerned about the baby iguanas (except that dead animals should always be removed immediately) because short periods (overnight) at room temps should be fine for them - they just won't feed and digest at those temps. But once the heat is supplied, it should be offered in such a way that they don't smother their cagemates.
I was more concerned by some of the really scrawny Tokay geckos, monitors, and a few other unsaleable looking animals I saw at the dealer's tables. I didn't really notice anything terrible at the breeders' tables. It is usually wild caught stuff at dealer / wholesaler tables that looks bad. I did look at the same table that the adult corn came from. The other adults I saw looked good, at least from a quick passing by. And a couple other customers came by with adults from that table that they wanted me to check the sex for them. Their corns looked fine. I think they just had one or more animals in bad condition that they tried to sell cheaply, but without explaining why they were so cheap.
I was not away from my table for more than an hour or so the whole show, so didn't really have time to closely observe who had what. But on the whole, animals looked pretty good, from what I could see.
I will be curious to hear what, if anything, you hear back from the promoter. Some shows have vets, some don't. I am not sure if there was a show vet at that show.
I am surprised your vet didn't pull of the ticks with tweezers. Didn't he give Ivermectin? I really thought the ticks would be gone by now. If they drop off without dying, they can re-infest your snake later. So be sure to get rid of them quickly.
Good luck with her.