The question: What are the best ways to water proof the house especially against major damage from water heater, fridge, dish washer, washing machine, plumbing leaks?

You will attract more tenants and more rent by providing laundry hookups or machines, especially in a single family. 

In my opinion Your marketing machine will be the difference between cashflowing or not for SFR.

Pipes freezing, machines being broken into, and people basically camping out there and tossing out their trash.

Just bring a white noise machine that plays non human audible sounds but scramble the ability of a microphone to record human voices.

There's just a lot of directions to go with this.for anyone starting to look at running Machine Learning against property/investor data...

It may not make sense to purchase a coin operated machine as they are soo much pricier than regular machines.

I rent the adjacent townhome on Airbnb, and only allow 2 vehicles there.All the huge vehicles on the street make it difficult to maneuver, and the optics look trashy on an otherwise upscale(ish) street.... ie one truck has had an old washing machine in it for 5 months. 

Depending on the setup I might shut off water to say a washing machine in the basement. 

For those that are interested, it took me almost a month to book a contractor (that I'd never used before) and the bid came in at $3400 for:interior paint (~1000 sq ft)patch drywall holesreplace outlet coverswashing machine and dryer hookup So, that's what $3400 will get you here in San Diego.