The bottom line I want to know is whether there is ANY other problem I could be having that might cause the results (detailed below) that led them to label my problem as celiac. Based on what I've read, all signs point to celiac, but I don't want it to be that!! (And I'd suspect that most of you won't have expertise to declare it possibly something else, but any direction to search would be appreciated.
Villous atrophy confirmed by biopsy is the "gold standard" when it comes to a diagnosis of Celiac Disease. And as someone else already mentioned, the only other thing that could cause it would be dairy, soy or corn intolerance. Lack of improvement on a gluten-free diet would only point to the need to remove more foods from your diet.
I also agree that normal Vitamin B-12 and Vitamin D levels are not a contradiction of the diagnosis. Vitamin D is mainly obtained through sunlight. Intestinal absorption has nothing to do with it. And Vitamin B-12 is readily available through meat and many other foods.
The fact that all other tests confirm the diagnosis pretty much negates the need for further testing. There really are no "zebras" to continue looking for. Or rather, you have a positive dx of Celiac. Any other diagnosis would be IN ADDITION to Celiac.
And I am unsure as to what you mean when you say you "don't feel sick like other people do". Exactly what prompted all of the testing? Was it screening prompted by someone else in the family being diagnosed? (In which case, a genetic predisposition would already be established). It is very rare that doctors test for Celiac without an initial visit and symptoms to indicate the tests are warranted. The diagnosis of Celiac usually takes a patient seeing 5-6 different doctors and about 9-11 YEARS of testing. You're actually one of the lucky ones.
Celiac is a clinical chameleon. Symptoms are widely varied (200+ possible symptoms). Some people have diarrhea, others are chronically constipated. And I believe that over half do not have the GI issues at all.
Reflux can be a symptom of celiac disease, but it can also be an indicator of other food intolerances or of too much/little stomach acid. The persistance of reflux just indicates that you need to continue investigating this portion of your symptoms outside of the celiac disease diagnosis. It by no means nullifies the diagnosis. You have Celiac Disease.
One of the best resources that can help you in figuring out the reflux portion would probably be the Related Disorders section on this site.
I am sorry that you are in denial. And I do understand the denial you are in. This diet is very difficult to get behind in the beginning. It will take about a year before it becomes second nature. There are many here who would love to have the positive dx you have received to reaffirm their decision to be gluten-free. It can be even harder to be on this diet when the tests don't point to the dx, but the resolution of symptoms on the diet do.
I think that in this instance, you just need to take it a day at a time. Life without gluten is challenging...but it does get easier. And keep in mind that some folks are asymptomatic...until they get diagnosed with stage IV cancer induced by undiagnosed/uncompliant celiac disease. And then, it is often too late to do anything about it. I've yet to meet a pancake that was worth that.