1) The answer to number one has been debated, and as you point out the examples on the embassy sites have no mention of it. I have not seen anyone post that they were not let in if it was not mentioned but it would seem to be easier if it is. I used QuickMD and they ask if you have had a the test. If you do they will put the results on it. If you don't have results they will say they are pending, but you do not exhibit any signs.
2) I have not heard of that. I will be using QuickMD, again. Others have stated that it was accepted and is done online for $75.
3) I'm using Qatar. They offer free rescheduling, which I have already used because my PCR test was lost or mislabeled.
Here is the list of semi commercial flights approved by Thailand.
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