So, the doctor's office called me back on Friday to answer my questions. Regarding the Total Serum IgA, the nurse said the doctor never orders that test, because it's too specialized and only GIs should order it.
Regarding the AGA IgA/IgG vs the DGP IgA/IgG, she said they don't know anything about how sensitive the AGA tests are vs the DGP tests and that they would have to call the lab and ask them. Based on what the lab says, the doc will decide if she will order the DGP tests (but she will not order the Total Serum IgA).
I also asked what could be causing the B12 deficiency if it's not celiac (we know I'm eating enough of it and we've ruled out pernicious anemia). The nurse's response was "some people are just b12 deficient." That doesn't make sense to me. If I'm eating enough of it, and my levels are low, there must be a reason my body isn't absorbing it.
They haven't checked any of my other nutrient levels, such as iron, vitamin D, etc. I pointed that out to nurse and she said she would ask the doc about it.
So, I'm once again waiting for them to call me. In the mean time, I've started to keep a journal of what I eat and how I feel. I had some pretty bad GI issues over the weekend and spent most of yesterday laying on the couch not really feeling like doing anything. I don't know if this is all in my head, like confirmation bias - someone said the word "celiac" and now I'm viewing every little thing through that lense. Or if I really have been missing/writing off symptoms for a while and now I'm just more aware.