Utilize tools such as market data and the BiggerPockets calculator. 

We just started the process of creating an LLC so we can can track finances and submit for tax purposes.

Depends on what sort of analysis you're looking for but here are a few I've found helpful:https://www.city-data.com/https://www.greatschools.org/https://www.recenter.tamu.edu/data/housing-activityhttps://www.neighborhoodscout.com/

I’ve implemented a 3-strike policy, 1st strike is a verbal warning, 2nd strike is a written warning, 3rd strike starts the eviction process for smoking in the units.

I recommend relying on actual data.

Re property size, from the data I’ve seen, it tends to be pretty linear in the Smokies.

Yes, right now Oklahoma City, Oklahoma is one of the top areas in the country for single family homes according to expert data analysis.

I'm going through a pre-approval process right now just out of curiosity.

I was thinking of this as part of the due diligence process prior to closing.

If you follow the process you can make your investment back on one or two deals.