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.

In some states the real estate license laws prevent this (as a sort of Buyer Inducement) while others say "induce away."

We recently received a picture that there are large icicles extending from the roof, and I am trying to figure out the most feasible and preventative way to remove the icicles and ice underneath.

It will be inexpensive, keep your good tenant happy and possibly prevent an infestation.