In these instances, you'd have to check things like flooring, plumbing for leaks, roof for leaks, hot water heater, and heating and air conditioning units. 

Plus a small cutting board and "hot plate" to avoid tenants damaging kitchen counters by chopping items or setting hot pots directly on them.Gail

They can use water from the hot tub or fill up a bathtub to have water for flushing toilets.  

She then got a message from the tenant yesterday that said: "I know the plumber came but we did not have hot water yesterday and again this morning.

A hot water heater might have a 6 or 12 year warranty, but you can expect it to last double the warranty.

They know the tenant base, median rents of different areas, how much to increase rent each year, ranges of repair costs (ex: tenant calls and says AC isn't working, no hot water, faucet is leaking, the HVAC system goes out).

Air Conditioning, if an city is hit or miss with A/C units does this play a large factor on rent and/or property values?

Let's just get the property furnished, a hot tub installed, and start making some money!  

I'm just pulling 6% out of mid-air. 

Also if you correctly read the laws in most of the states in the US and the federal statutes, creating systems as the one you are promoting would land you in the hot seat.