If the sites are larger than 1/2 acre (NOT AN EXACT NUMBER), and you are needing to develop the land (i.e. roads, utilities, mass grading) I would then recommend involving a civil engineer on a site plan and to do a more in-depth due-diligence. 

We are also utilizing the current office on site as our new headquarters.

We are also utilizing the current office on site as our new headquarters.Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Tenant does not want to pay utility charges till statement shows her date of occupancy.

Payment history on your utility bills, cell phone, and other types of bills can be used to establish credit. 

The owner lives on site, has owned for 15 years, and pays ALL tenant utilities (not common in Indianapolis).

She makes enough from social security to cover rent and the utilities, but not enough to cover three 3 times the rent.

You may find that it's simply not worth the cost of the repairs or that the potential rent from it will not be worth utilizing it as such.3. 

With a Vrbo you can also write off the utilities.

They have a network in place already you can utilize.