Students and traveling nurses are two groups that I've known to look for furnished units.

My concern is, if I buy a duplex 1)am I required to allow usage of a garage on one side and 2) in the case a tenant leaves without removing their belongings from the garage do I have to hang onto it?

My wife and I are both in the travel business - She is an agent and I own a travel marketing company that does SEO for 7000 Marriot hotels.

Maybe you live in a touristy town where AirBnB is highly profitable, maybe there is a high demand for student housing, maybe the local hospital needs furnished apartments for their traveling doctors etc. 

I travel 4 days per week and I've run into tremendous challenges managing remotely.  

Some questions I am trying to answer are:What demographic of travelers are staying in these listings?

I currently have several cards that combine to offer me roughly $3000 worth of free travel every single year that I can either use immediately, or stockpile it for my big world tour once I retire.  

If those lots are not counted in your Certificate of Zoning, you could appeal that they are wrong on the count (but you'll need a municipal lawyer to represent you) or you could go buy a $500 travel trailer and put that on the lot and see if you can get a city approval for electric hook-up (and if not, you're back to the attorney again).

I would be traveling from Toronto, Ontario with my wife.

You could just increase rent some to cover the washer and dryer and usage.