I know real estate is a long term play but you never know when you'll need access to that capital.There are turnkey companies out there that handle the entire process for you from top to bottom so it makes for an extremely passive investment.

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

As Columbus cements its reputation as a tech hub, the ongoing and planned investments by major tech firms are likely to ensure long-term growth in the local real estate market.

Check out Norada Capital with a simple no fees structure and 12-15% annual yield depending on how much you invest.  

Are there any resources that help explain what type of terms we should ask for?

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

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). 

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?

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.