All good questions. The reality is that there is too much going on to enforce. In general the DBD and the police focus on the most profitable cases that are worth multiple millions or much more.
https://thethaiger.com/news/business/thailand-tightens-foreign-business-laws-to-curb-nominee-practices
Foreign hotel chains work on the franchise model, with the local owner (inevitably a Thai citizen) paying a fee for branding, marketing, etc.