The buildings are swaying and moving. Totally normal, all designed and planned. No building stands completely rigid without moving. There needs to be some flexibility to prevent damage
In theory if you do remote work in Thailand while teaching English it would be illegal, as your work permit would only allow you to do the type of work on your permit. Education visa same thing. Probably wouldn’t ever catch you with remote work but you’re not allowed to work in Thailand on a DTV visa, but you could do remote work. Not sure how schools for kids work on DTV.