The way I look at it, an ounce of prevention is worth a pound of cure holds true in the majority of cases especially when it comes to maintaining a commercial property.

The are strict license requirements in my industry too (home inspections) but that doesn’t prevent a non-inspector from owning and controlling a home inspection business. 

This will prevent headaches down the road.  

We try to stay preventive with this sort of thing...upgrade to aerator...and ensure the leach field is up to par when purchasing...this is a good example of how bad things can get without proper due diligence and maintenance.

I tend to move fast and take massive action to prevent myself from getting into analysis paralysis, self doubt, or boredom.

You will at least have a judgement against them and while you may never see the $5k again, at least it will go on their credit and possibly prevent them from doing it to the next person.  

This would also prevent people from going in other guest's rooms. 

@Matthew ScottThere is no need to spend time and money preventing mold if it isn’t a problem now.

We personally manage our properties so we would provide the removal ourselves if we planned on keeping the dishwasher and require that the tenant gets the new dishwasher professionally installed and remind them that any damages from installation could possibly come out of their security deposit.From my perspective, the only thing I would be concerned about is the new dishwasher being hooked up correctly to prevent water damage to the floor.

They have specific noise levels which would be far louder than walking on hardwood floors in the middle of the night with clogs on.