The worst are three person partnerships.The most stable are 10 or more.

I was able to package three of them in one deal, which ended up breaking even/not profitable (A little bummed on this one since I think the buyer (an investor) won the better side of the deal in terms of gaining equity on the houses).

As @Greg Scott said, the best way to manage is to have two or three windows each week and you set all the showings at the same time.

Three years ago, at the age of 18, I partnered with my parents on our first single-family rental.

For context, we own three duplexes in Indianapolis and they ALL need work done.

He went upstairs and now the cold was in the main room, and the lights started to flicker again, and the door upstairs slammed twice, three times in quick succession.

I oddly enough started with Rich Dad, Poor Dad, and then went on to three more books from Bigger Pockets publishing who all mentioned that book.

(Keypad lock, thermostat, etc) I have ring at my own personal home, I know of another Host who uses Google Nest. 

I strictly use them to trade into places I really want to go and I can never, ever beat the price I pay for a week as compared to normal rentals rates which are three to seven times higher per night.  

It would be wise to have at least three months of rent saved up at all times to cover the unexpected.