As a park owner what are your thoughts: what prevents me from paying $$ for this mobile home only to have the park owner tell me I can't rent that space? 

They tend to be the most finnicky with the variable of if the tenant knows how to maintain them, make sure to have your exhaust cleaned after every tenant move out because tenant do tend to clean out their lint filters regularly from my experience (this will prevent lint fires). 

I can prevent those pain points.

So just fix it early while the big damage is still easily preventable. 

Unfortunately, the rules around them are designed to prevent exactly what you're trying to do.

Maybe the release is healthy and prevents an internal malignant build up.Whichever way people choose to deal with dishonest individuals I think it is a reality that is this business you will run across them on a regular business.

Are there any alternatives to the 1031 exchange he can utilize to prevent paying capital gains taxes? 

I prevent this by building a automatic 3% increase into my leases at renewal.

What can you do to prevent water vapor from traveling from the shower into other rooms and causing mold in the bathrooms or rooms around the bathroom?

Do preventative maintenance on appliances and air conditioners.