His insurance should cover it, then if he wants to push liability down the food chain that's on him.

Food for thought:  the $5000 you are expecting to spend on repairs, are they needed maintenance items or more cosmetic type improvements?  

I am not trying to kill your dream, just adding some food for thought. 

Then I’d look into a pest control technologies degree because they will leave food out all day which always attracts vermin .

The fact that so many here are saying "what about" isn't a sign of dream killing...it's free food for thought. 

I think you need to put your foot down and stop catering to every whim of your tenant. 

Also travel, food, gas ect can be written off when traveling from ine to the other. 

Before our food even arrived we discovered a handful of coincidences between our lives (both of us had two year wedding anniversaries that were 3 days apart).

This can be achieved by not catering to the higher end properties and instead work the middle to slightly under market where houses can be purchased for a much lower price yet still ask for very good rental rates. 

Which includes food insurance, home insurance, and PMI.