Below is a small reminder of the true law in Thailand, foreigners who are owners of a business be it they have legal Thai company limited papers or the rental agreement is in their name for the establishment, if you are receiving profits from the business this can be classed as working with no work permit as you are obtaining monies without paying the correct tax that a work permit holder would so beware as it can be a reason to be arrested by the Immigration bureau, in most countries avoiding paying taxes would be an offence.
Foreigners feel in Thailand they can own a business but as long as they do not work in the establishment then this is fine “wrong” if you are making a living from the business then the correct taxes a foreigner should pay have to be met if not you are always at risk of arrest so preempt a situation and try to obtain a legal work permit or the business should not be in your name.