We can make rules and laws, but can’t prevent people from breaking them.  

This code is designed to prevent swimming pool accidents."

He brought me $500 in bills for leveling spacers and thinset and redguard/crack prevention.

Probably just meAnd when you do have that tenant issue, that then chews up 100hrs of your life in a matter of weeks, and your flipping out over how insane everything is happening, that is when you will say "OMG F-this, someone else can deal with this". 25% of what a property manager does is PREVENTION and PREPERATIONS for things going bad. 25% is knowing all the things, ALL THE THINGS.

It may prevent them from qualifying for another rental, a home loan, car loan, credit card, etc.

However, it is important to note that the IRS has strict rules and regulations in place to prevent abuse of the depreciation tax benefits.

It’s probably legal to prevent them from having a guest in a common area.

The reason for this is to prevent people from getting a good deal, immediately refinancing, pulling all of their cash out, and having no "skin in the game".

If they are trying to put a lis pendens in place to prevent you from being able to sell to anyone else, a quick letter from your lawyer will usually clean that up. 

I feel the topic of preventative exterior maintenance is rarely talked about.