Fortunately for me, the income that I will be bringing in is not taxable in Thailand (specifically excluded in the tax treaty), but that is a very good warning for most people bringing in retirement funds!
We tried the DTV route, but the hospitals/doctors that I spoke to (including the one I consulted in November) all wanted to only set one appointment and then develop a treatment plan. I was under the impression that I would need to have a longer treatment plan to make the DTV fly and didn't want to waste time with getting denied.