My lender just informed me that they now cap their count at 10 per "household".

There aren’t a lot of high paying jobs in the area as well (median household income 58k- https://worldpopulationreview.com/us-cities/st-george-ut-population) , so you’d be relying on people working remote should you have to rent to a longer term tenant in an economic downturn.

A 22-year-old E-4 makes roughly what a college grad at an entry level job makes, $45-50K/yr, around what the median household income in the U.S. is ~$51K.

If so, does the net proceeds from the property sale contribute to this number, or is this just in reference to our AGI as a household? 

If there is a decrease in population I imagine its more because smaller wealthier households have replaced larger less wealthy households.

Median Household Income Growth - www.City-Data.com4.

The metrics that I have incorporated into my are as follows:- Median Home Value- Median Rent- Median Household Income- Poverty Rate- SNAPS (Food Stamps) Rate- College Graduation Rate- Vacancy RateI have chosen these because I believe that these metrics give the best indication as to the "risks" an investor will face when selecting a location to allocate into. 

One thing to keep in mind, the city is implementing a limit on how many STR. 5% of total households can operate as an STR.

The Housing Authority will review the household makeup (I.e family size) and income. 

You can take a look at their site and they have options through which you can filter equity %, household ages, last market sale date, etc.