I wouldn't know about the legal structure you would like to invest your assets. Do it as you please, these things vary country by country too. The core concept is that you need to have some kind of structure for handling the money and a method to keep that structure in check.
The problematic part starts when someone acts outside of this structure, like employees who take customers money and invest with it without explicitly having a right to do that.
The problematic part starts when someone acts outside of this structure, like employees who take customers money and invest with it without explicitly having a right to do that.