If you apply yourself, send them a follow up email stressing the urgency. Also, follow up with your hotel to expedite the process, as they are part of the Thai Pass approval process. Sorry to hear of your loss.
(1) RT PCR test is usual requirement of airline and or country. Usually 48hrs or Thai Airline 72hrs
(2) since you fully vaxed, Test & Go scheme could be feasible. Which means u are tested upon arrival and need to isolate till result is revealed. Usually 6-7hrs. Then day 5 u conduct a self test.
(3) the official application platform to formalise your visit to Thailand. Ie. Uploading your vax, insurance coverage, hotel booking etc.