you could buy a second hand bike privately and ride that as long as the registration and taxes are up to date. However, you won't be able to re register in your name.
The day you arrive and check in is not counted regardless of when you check in. I went through it back in December and in total was 15 nights and 16 days.
depends on where you go to do the extensions. When I did my first one (30 days) I asked if I could get the 60 days covid extension and they said no I had to get the the entitled 30 days first. At the time I read on some post that some people were able to get the 60 days covid extension right away. I went to Samui Immigration. FYI the last day to be able to get a 60 days covid extension is May 30th. Unless things change and they extend this date as they did many times before. But if I were you, I would go before the 30th just to be safe. Good luck. As for TM30. I've never been asked for it.
Yes the 30 days visa exempt option is available for certain countries. However, you still need to apply for COE which involves having a flight and ASQ booking along with insurance.
no, I was at Samui immagration a week ago and they said I had to get the 30day entitled extention first. Depending on the situation near the end of the extention, I could come back 7 days before it expires and apply for the 60days covid extension.