I've used Thai Visa Centre before, they were really excellent. I have no idea if that's who contacted you, or if this exact company does marketing in that manner. If you need an agent I would contact them directly, not through that email..in case they've hijacked the real place's system.
You can use a rapid test, but not a self-test, it has to be performed at a lab/hospital/clinic, with an official results document, and done within 24 hours of your departure. PCR can be done within 72 hours of departure.
No, not true, except maybe in a very local hospital? I've had surgery alone in an international hospital, no issue whatsoever. I was in a private room.
Centre Point brand hotels are really good. I stayed at Centre Point Sukhumvit 10, they are very responsive, but have heard they are all managed very well.
Your day 1 hotel should've given you the test for day 5, you do it yourself, take a photo then supposedly upload it to the app...but never really works..some people send it to the day 1 hotel, and they upload it into the system for you.
Yes, Centre Point in general is a great company. I used Centre Point Sukhumvit 10, also excellent. Booked directly with hotel, very responsive, everything great.
Even with the mandatory pre flight test, people arrive positive everyday. That number will now significantly increase, and those people are going to be infecting people on the plane.