See what it is that they need the most help with and offer to do it for free- this will allow you to gets hands on experience with an already functioning business. 

I would not recommend it from a functional kitchen perspective.  

You don’t see this in syndication books because it’s not typically a syndication sponsor’s function.  

It tracks well with what I have heard from some Airbnb specific managers in my area and was so easy to use (the free functionality, I haven't messed around with the paid stuff).

I have several SFR's that I manage using Cozy....I am happy with the functionality for my needs to this point.

The BEST way to protect yourself is to know the law, obey the law, ensure the property is safe and functional, and treat people honestly and fairly.2.

However, you very well could be sued for refusing to rent an upstairs unit to someone because YOU didn't believe they had the necessary mobility/functionality to live in an upstairs unit. 

I would take the time to clarify expectations in writing and also to make an agreement for what you all believe should happen if for any reason he is unwilling or unable to fulfill this function in the future. 

Appreciation is largely a function of time.

While some of these buildings fails in high winds and huge snowloads, that's more of a function of engineering.