Question is, if I have the means to put a high enough down payment on a house to be cash flow positive (assuming my expense estimates are accurate, etc.) is that something that I should do?  

This indicates a strong market for short-term rentals.Revenue: The average revenue per available rental in Red River Gorge can be estimated using tools like AirDNA.

These softwares have a lot of functionality, but honestly there is a steep learning curve and the functionality is probably overkill for most rehabbers.FlipperForce - Web-based House Flipping Software built specifically for flipping & rehabbing houses w/ Estimating, Gantt Scheduling, Task Management & Budget ManagementGeneric Project Management SoftwaresThere are nearly an infinite amount of potential generic Project Management softwares available that provide powerful functionality for managing project schedules, tasks & documents. 

It's only for the most experienced investors to have any chance.

Gaps in rent payments or undisclosed tenant issues should have been red flags.It’s good to see the OP trying to help their client navigate this, as acting promptly is critical for any chance of recovery.

Quote from @Roger Garner:Multiple estimates and get some photos of their work too.

By any chance, do you know of any meetups or groups in the southern Tennessee area?

Maybe I'll get the chance to try someday. 

Now that I have explained all of this to you, is there any chance you have an answer to the question I asked?

The rehab estimate seems very low and the ARV seems really high in my opinion, just based on a tiny bit of research looking at what this property was listed for recently (it hasn’t sold), and what the surrounding similar properties are worth (~$250k).