I stay (live?) at a certain hotel while in Bangkok.

 

Will there be a problem at CW using the hotel's address as my Thai address on the TM when I extend (for the first time) my permission to stay on the basis of retirement?

 

Some retirees I know are also a little uncertain about this and are thinking of asking their hotel to provide them some kind of letter stating they have been living at the hotel.

 

Also, since I will be staying at the hotel, will I have to provide a TM30 when I go to CW for the extension?

No problem to use a hotel address when you apply for the extension. You will need proof you are staying there on a somewhat long term basis.

The hotel should be doing the TM30 reports online. Ask if they are doing them.