The government retracted their decision to remove the pcr test on arrival. The only change that got approved was the for 7day quarantine is now 5 days. Everything else stayed the same. So if you are fully vaccinated and are from the approved countries then you still need to book a 1 night test and go package.
Depending on which country you are from you will be able to enter under a 30 days visa exempt stamp. You will still need to do the Thailand Pass to get your QR code before you arrive.
yes but it is as you said, they want you to provide a valid reason for wanting to re-enter the country. If you are planning to stay longer than 90days then they want you to get the Special tourist visa where you need confirmed pre paid bookings or lease contracts. If you manage to get approved for the METV let us know because I think a lot of people would like to get that, myself included.
METV was not available in last year and a half because borders were closed and the stringent entry requirements put in place. Maybe when the borders open up fully again they will allow easement of the METV.
Agoda bookings are accepted. After confirming the booking with Agoda the hotel will contact you and ask for a few things to complete the registration and then they will send you the reservation page that you can submit for Evisa or Thailand pass. I haven't seen any Bookings.com being accepted. Go with Agoda if you don't want to deal with the hotel directly.