It looks like you have a business loss which you can use to offset other forms of income.I don't think you sold it less than its worth, you likely tried to get as much as you can.Squatters decrease the value of a home, especially if you are selling the house with them in it.

If you pull permits and renovate, both your property taxes and insurance are very likely to increase, causing your cash flow situation to decrease.

On the weekday availability, I decrease the required minimum stay and the price.

I agree with many of the other members of BP in this post, Detroit is not an easy market, still many pockets in the city, poverty zones, local Detroiters codes that must be attended, but at the end of the day is a powerful and big American city that is coming back (see GPD/Capita increase, unemployment rate decrease -still high for U.S. 9% in comparison with a national average of 3.9%-, an improvement in the family household income) that can make SOME investment thesis work properly. 

I cant find a consistent source for a long period of time, but glancing at some different sources, the largest decrease I can find on a national level is a 1.7% drop from 2008 to 2009.

Title insurance claims or lawsuits can take years to resolve and if you didn’t have insurance it can easily cost you $100k especially if it’s someone challenging lien position when asset value has decreased

This shows that numbers have slowly (not a drastic change) started to decrease as of last year for visitors at the park, which could effect pricing per night.  

I’m really drawn to REI so I can spend more time with my family (spouse and 2 kids), retire a little earlier, and decrease the constant stress from my current job.I’ve owned my home together, with my husband, in Boston, MA (purchased Jan 2020) and also a STR in Ludlow, VT (purchased Apr 2018) near a ski resort.

Alternatively, you can go back further in time and try to apply a percentage increase or decrease based on what the market is done in that area.

This should relax as we expect to see rates begin to decrease.