Is it required to have a broker or real estate license to start a property management company in Michigan?

It isn't required if you want to OWN IT. But you can't run it because you don't have a property management license (separate from broker or trading services license in some places). So you would need to hire a broker who has the property management license in order for your company to work and for the employees under that broker to be eligible to work in property management (with the exception of the receptionist, etc).