Any "exotics" veterinarian that has any reliable knowledge of boids who decides that testing for IBD is pointless, clearly has no clue as to what they are doing. Then again, a so called "exotic veterinarian" that does not even have an option to label the animal as a reptile rather than an avian (splitting hairs to some, but to me it is pretty telling) is not someone who should be looking at any reptilian.
Give the nature of most snakes, it would be incredibly difficult for any veterinarian, no matter how long they have been practicing, to diagnose most anything in a neurological sense on a reptile with just a simple examination. X-rays would be something to seem standard, as well as an attempt for a fecal and some basic testing to check the neurological competence of an animal. The only way they would just say "Nope, sorry, none of this matters, the snake is going to die" is if you refused any type of further treatment no matter how inexperienced the veterinarian is with reptiles, which I am sure you did, which is rather unfortunate.
When veterinarians are in school, there is very minimal training and teaching on exotics. It is up to the individual themselves to spend the extra time learning how to deal with these animals or just becoming specialists in one (in this veterinarian's instance, avians). Just because they can figure out what is going on with birds and just because they "bred ball pythons" means jack. Breeding ball pythons is not difficult and qualifies no one to be able to medically diagnose major issues with them.
The veterinarian you took this animal too clearly has no knowledge of IBD (not that the animal is likely to have it anyway) and clearly has no knowledge of Spider genetics and likely has not gotten the full story from you. I love how you keep saying this animal is going to die soon and its body condition is horrible when all I see is an overstressed Spider type animal constantly being messed with by an inexperienced keeper who made several major mistakes that likely attributed to her condition. The only way she will die is if you do not properly care for her which, at this point, appears to be the unfortunate fate of this animal.
Two years of keeping? People with 20+ years still learn new things about their animals. You know the bare basics and I mean the absolute bare basics for this animal and it is blatantly obvious in your postings, your handling of this situation and your constant abuse of this animal (messing with a super stressed, ailing animal constantly is abuse). You are clearly unaware of the fact that stress can and does kill these animals and the best thing to do when they are exhibiting problems is to get them properly treated and leave them alone in a quiet, temperature controlled, dark enclosure. It makes them feel secure and it helps in their recovery.
People can speculate on what happened to that animal until the cows come home, but a simple fact remains: the fault of her current condition is unknown because you are unwilling to find a veterinarian (or you simply refused treatment) who can properly observe, diagnose and aid this animal. If it was IBD, there is a good chance that snake would be dead already and her movements are really not indicative of it. Is it neurological beyond a genetically flawed animal just exhibiting the known flaws of his genetics? I do not know, neither do you or anyone else. What is known is that you have an animal that was eating, that is going into shed and that is displaying signs of a healthy snake beyond the weird quirks associated with its morph. Not to mention, you force fed it water. You can try and say you did not force it to take the water all you want, but it was against its will. It's not common to see these guys drink so for you to claim it will never drink is ridiculous. How do you know? As for it not eating? It just ate, it is a baby ball python and you are stressing the poor thing out beyond belief, of course she is not eating.
PayPal is not likely to side with you and I do not fault Rob for nulling out his ToS. Personally, I wish Rob would take the animal back just to get it out of your hands, but I understand why the situation has become what it is. You should really take this as a hard lesson learned, reevaluate your aspirations on this hobby and learn about the animals you are keeping better.
You also need to find a qualified veterinarian who can deal with snakes in your area.