I guess my challenge right now is to define the strategy and balance all the factors, such as job and population growth (value increase), cashflow (demand & supply market, interest rate, property tax, maintenance cost), and risk control (insurance etc). 

OH is one of the states where lenders sometimes require that you buy out the prepayment penalty, which in turn will increase your rate and make it more difficult to cash flow.

At no point does there appear to be an accumulated balance but rather just a series of payments coming.

What you could doIs continue to pay that loan and have the owner also select finance you the balance.

This is the point that in my mind the house has reached a balance point and is stable.

As noted, commission are always negotiable as are brokerage options (full service to discount companies that pretty much just post it on the MLS and you work with all calls, offers, etc) and an agent can go over likely net out scenarios with you and give you an idea what you likely will be able to net after closing expenses and paying off the mortgage balance. 

I'm struggling to generate extra lead flow from builders, mostly because it's so difficult to identify folks that are doing ground up, business purpose construction. 

Cash flow, equity growth, or a balance of both?

The key is balancing protecting your business with connecting as a human being.

The issue you will have is that finding out what a property actually rented for is difficult.