@Larry Nielsen with the proper screening system, whether S8 or cash-paying tenants - doesn't matter:)

She is robbing the system.

Be sure that you have a differentiator that makes you unique against other homes in the market.

For the project I plan on creating a system to address every aspect, step-by-step, of increasing the value of multifamily properties by making improvements that increase each property's net income.

Not only is this clearly something that tenant is doing , but the plumbing is hooked up to a septic system and septic systems do not break down tampons. 

The real question has to do with  if you are prepared to do what's required to learn the foundations of real estate investing, strategies, tactics, financing, title, escrow, marketing, deal structuring, develop acquisition systems, investors, associate networks and management of properties, rent collection, cash flow, taxes, etc.This is all took me a lot longer than one year, but you might be very dedicated. 

And that his understanding of business and economics enabled him to lead our country to establish the free market based system we benefit from today. 

your system probably applies well in really dense areas but maybe not in less dense.   

Example: A backsplash that is a different color from rest of the kitchen (a warm green or red against white and grey walls), a tile that has a unique look or pattern to it, crown molding on cabinets, or a unique light fixture.

I work for KW and we belive in MODELS & SYSTEMS.