Taking Athens as an example, the Assembly seems to have had wide latitude to rule as they pleased on a huge variety of lawsuit. The ruling class was heavily pre

Taking Athens as an example, the Assembly seems to have had wide latitude to rule as they pleased on a huge variety of lawsuit. The ruling class was heavily preoccupied with the practice of law and rhetoric for the purpose of defending and prosecuting these suits, which seem to have been extremely common. I think it's fair to guess that yes, any upstart business would have required the consent of the Assembly (the government) in order not to be ruined by suits brought by their competitors, which probably means staying on good terms with at least some of said competitors and likely doing a lot of political work before launching the business. And certainly taxes would be collected. Plus, if you were in Athens odds were "you" were a slave. So the state's just a bit involved in your (in)ability to start a business in that case. Then there's Sparta with its requirements of state service and bizarre, heavy-handed property laws. And again, you're probably a slave.