To my surprise the seller left the refrigerator, washing machine, Hoover vacuum cleaner, a jar of pennies probably $25 a plant on the fireplace with a card addressed to the new owner wishing me much happiness in the new home.

Are you ok with multiple people being in and out of your kitchen space and refrigerator all hours of the day/night?

The people booking will just pay you a flat rent.Biggest problem you will have is that you need a full service kitchen with refrigerators and stoves.

First a manager informed me that I needed to purchase a larger refrigerator or the tenant was sure to move out.

Got a complete appliance package for $1700(side by side refrigerator, stove, dish washer and above stove microwave).

Do your costs include appliances such as refrigerators, etc.?

On the other hand  during a reno another investor in a local beach town was told a refrigerator made it an illegal kitchen gotta love those idiosyncrasies.I would say whatever  you decide even if it is not required you should plan on adding egress from the third floor in your costs. 

Gross:The top of a refrigerator was covered in dead German roaches, to the point you could barely make out the color.  

Who's responsible for cleaning the gutters and changing the water filter in the refrigerator (which should be yearly?)?

A prime example of this was when the filter for the refrigerator water dispenser cracked and leaked onto the floor causing some damage to the vinyl floor.