Safety systems     -  sprinklers, fire or burglar alarm, emergency lighting, etc.I would ask for Loss Runs (reports detailing claims made on the insurance policies).  

I don't mean to scare you, but having an emergency fund is truly essential to avoid having a small problem turn into a big one.  

You are also looking for emerging real estate markets, tracking the data year over year to compare it.

Also, make sure your operating expense includes housecleaning for each booking, maintenance, utilities, and if you are not local, someone who can act as a guest contact or at least emergency contact. 

There was an emergency happened to him right around the time the rent is due.

Another aspect of this is parasitical family members who are suddenly "close to you" and need accommodation because of some unexpected and horrible and unfair emergency. 

Lower cash flow can be worth it for an emerging market or better yet a market that appreciate heavily.

A contract can be useless (sometimes it is in the US too :) ).Currency exchanges, inflation concerns, especially in emerging/developing nations. 

Or often someone will pull cash out to free up down payment funds for a future Rental property, 2nd home or simply add to their emergency funds, etc. 

I also write an introduction letter saying hello and my name and emergency contacts and where to report repair requests and what to do if there’s more of an emergency type situation that we need to deal with not like a 911 situation and what to do with rent, where to mail it or electronic payment instructions.