You need to write down a business model to adhere to, or burn it into your brain.

BRRR is great but if you burn through operating funds you won't be expanding, which leads to needing to know your full goals.  

I have a Gatlinburg cabin that burned to the ground 4 years ago. 

Your earnings are almost exponential and the investment is bulletproof during market corrections since during market corrections multi-unit properties actually increase in value while single family homes depreciate.Don't burn the candle at both ends and someone like yourself reminds me of the same scenario I see over and over.

In March my tenant burned down my house due to "careless disposal of a cigarette" per the fire report.

Long delays in places like Dallas can cost you a lot of burn rate. 

Wood burns and sheetrock is fire-resistant.

Also check if the wiring is aluminum, I'm not saying don't buy an aluminum wired house but I don't like the idea of my rental properties burning down and if you can avoid it I would unless the deal is sweet enough.

Berwyn and Forest Park both do this a lot and what it means is your unit is legal unless the place burns down more than 50% or goes vacant for a year. 

We're looking into house hacking as a way to start, but we fear it might be too slow of a burn starting at age 29 that might not pay off in the end, especially since we don't want to live in a duplex forever...we have to get out of it somewhere, somehow.At $3600/year, it sounds totally unfeasible to do anything beyond our brokerage $500/month investment as any sort of savings for anything, whether benefitting the house or possible future expenditures and this has been bothering my mind for awhile now and created a lot of stress involved with the house.