Also, the term "house hacking" is generally used for your owner occupied home (renting out rooms in your primary home) and that income cannot be used to help you qualify (it is considered boarder income). 

If your rental rate is below the market anyway, a Tenant might consider this to be win as they would get the lower rate in the beginning and just rise to the level they were looking at everywhere else.Step clauses can be written right into the lease, or created by using 3 month lease terms with an auto-renewal at the step up rental rate price. 

The term "reasonable" is going to be redefined.

Is it for a shorter length term than the normal 30 yr?

Short term rentals in St Pete are technically illegal but it doesn’t stop hundreds of other investors from doing it.

In my mind sub to is for short term .. long term rentals is very problematic for many reasons. 

Let's roughly say running electric line is $10kInstalling underground propane tank 1000gal is $10kWhat's your experience heating with gas vs electric in terms of warmth?

The East Rock area of New Haven (near Yale) is a huge outlier in terms of pricing, very expensive. 

In terms of finding a property that "works," I think you are absolutely right, there are probably better markets with more reliable cash flow.

Long term hold.