Everytime a new victim comes forward it increases the chances and shortens the timeline for something being done. (800) CALL-FBI and (800) SEC-0330. 

Investing in the right neighborhoods can increase your odds of success.Also if you look at the appreciation rate in Cleveland and Dayton over the past 10 years its actually quite similar to the cities of Columbus.But I do see your point of being careful in "declining population cities".

Furthermore you can vastly increase your returns through leverage using a non-recourse loan but that will definitely trigger UBIT but again the numbers can still make a lot of sense. 

My guess solely looking at your numbers is that it's an older/distressed property which means you have to account for more costs in capex. 2nd thought being it's not in the best of neighborhood then you'd have to take into consideration lower quality tenants/ neighbors and maybe increase expected vacancy and late payments.

I did most everything I was supposed to do, increase my income, decrease my living expenses, save cash, etc.. 

Without actually building the 3rd unit, would this new triplex eligibility increase my property's value? 

I am unconvinced that the new administration will meaningfully address the deficit and US credit will continue to erode gradually, contributing to rising rates.

Just make sure you are saving towards those slow months during the peak months, buy a deal at the right price (don't overpay just because its a turnkey STR or you think it will make more money than projected), and look into ways to increase bookings during those slow months with some marketing and operation tweaks. 

They had an unfinished space counted as finished space increasing the size of the home by ~10%.

Buying more properties, if buying correctly, simply does NOT increase your DTI or at least in my example above much at all.