When I performed the walk through prior to the purchase, they had pictures and posters on the walls and other large items such as the Sofa, so it was a little difficult to identify all of the hidden damages.

Re-trading the price using your inspections is typical from some, but keep in mind that it should only be used when items that were totally hidden from your eye are found.

There are so many hidden things you wouldn't know until you own the property.

Where did they get the wiring instructions? 

If the tenant produces doctor orders with specific instructions perhaps then the landlord can consider buying that toilet out of kindness if not legally or contractually required. 

(Not hidden)2.

I hand them a letter with instructions for paying rent, contacting me, etc.

In my own home, I prefer Samsung's, but for the one beach rental I have a Samsung in, the guests are always having problems with the menu function (even after making instructional videos).  

What was needed was a firm Contact Price.Even then, a firm Contact Price is very often subject to situations like acts of God and hidden conditions.

They can help you out along the way as well. also, you do not understand all of the hidden fees as a real estate professional as well.