If your strategy is buy and hold and your numbers work you may not have to worry about short term market fluctuations.  

You are not so much concerned about how the pricing of homes fluctuates.  

Interesting topic.In my units it's gas but it's common for my area except the dryer is electric.I have some tenants that love electric and others love gas and hate electric.It will be based on their past individual experiences dealing with utility companies on how they feel one way or another and what they grew up using.So I just go with what's common for the area.I do agree with low income tenants that have wild fluctuations in income that they will try some risky things to get by sometimes.Higher income tenants do not tend to think of doing such things as much is my experience.

Don't know if these are clerical errors or rent price fluctuation.

Mold is a function of humidity not temperature fluctuation.

So there is a lot of fluctuation.

Residential is tied more to comparable sales and fluctuations with speculation.Commercial is tied more to the income approach and increasing cash flow.In residential your cash flow will be tied to what kind of property you want to own.

His credit is in the upper 700's to 800; mine fluctuates between between 680 and the mid 700's as we put rehabs and down payments on the HELOC or credit card  in my name and then pay off when we refi and rent collected.

What I mean by this is buying a property that offers enough room in equity, cash flow, etc. to the point that you can still be positioned correctly regardless of market fluctuations.

However, it's important to remember that these numbers can fluctuate and there are no guarantees.