Wife and I heard of a potential family-deal, where current Detroit Lakes owner wants to quit the snowbird game and go full-time-Florida.

Absolutely agree, if it fits your intent.Come up with your own game plan, which starts by learning. 

At this stage of the game for you, I would focus on banking as much money as possible and absorbing as much information as you can on real estate.

He is the best in the industry.

There are also contractual things that can be done (discuss with an attorney who is knowledgeable in your industry) such as hold harmless, requirements that if they hire a sub that the sub must also meet any requirements for the insurance, etc.

Ideally, we could find a brick industrial type building where we could rent the ground level commercially for about the PITI, and live close to rent free above in a loft like space.

Uber and Lyft fought the taxi cab industry and up-ended that industry. 

Being licensed means taking on a legal duty that limits one's ability to take certain actions other investors can take.I know people who became licensed stock brokers but never got a job in the industry.

This is to prevent people from being cute and playing this short, 15+% return game.

After being an active broker for 30+ years, I would encourage you to become a licensed agent and then broker.The experience of inspecting many properties on a daily basis, learning the listing as well as the selling side will only up your game when it comes to negotiating with a seller who's property you want to buy.Some of my best and most profitable 'flips' were because I went out on a listing call, knew the property values and was first on the scene.