Currently there is a non-conforming bedroom along with a total of  1,000sqft of livable fully  finished and well lit from natural light living space, including a bathroom and laundry — and a kitchenette area.  

What you listed above puts you light-years ahead of 90% of people your age, but you came here for advice, not kudos, so let's get down to it...First, you need to decide your risk tolerance.

Most of Indy is covered by two utility providers, Indianapolis Power & Light(electric) and Citizens Energy Group(Gas, Water, and Sewer).

You should get input from local agents on what rental rates you can achieve in light of the slightly unusual location and you may want to factor in some additional vacancy if you want to be conservative.

New carpet upstairs and in the basementNew laminate downstairs Brand new appliancesAll new kitchen, including granite countersAdded a pantryDemolished two downstairs bedrooms and made into one with an en-suiteMaster bath with tile floor and a HUGE tile showerNew electricalNew plumbingNew ductworkTile fireplaceChalkboard/magnetic wall in the basementNew landscapingNew facia boardingNew lights I lost track of how many new windows I would post pictures here, but it appears we can’t do that on mobile (Mindy Jensen can we get a patch/update for that?)

You want to tread these waters lightly 

With 15 years it's just long enough to make the hold less likely...or even if I sell in less than 10 a new buyer can also see the light at the end of the tunnel and may pay without too much of a discount on the price.I attempted a simple analysis of a moderate vs low income ADU project purely as an arithmetic exercise.

A light/cosmetic bathroom renovation could cost as little as $5k-$10k.

Use that one time consultation to define:- An interior paint color scheme (walls, trim, ceiling);- A cabinet/countertop color and type;- Flooring types/styles/colors (carpet, vinyl, hardwood, tile)- Specific finishes (lights, fans, plumbing fixtures, etc)- AppliancesOnce you've defined all these things (I call them all "finishings"), you can use the same ones in *EVERY* house.

It is not a light read though.