Yes there are builders out there who are building new structures on old but functional sewer lines.

Property taxes are a function of the cost, not much variability, insurance is basically priced on the value of the house.  

Old 1961 house, with separate entrances to the upper and lower level; I suspect it functioned as an actual duplex at some point.

Was the bathroom functional prior to gutting it or was it just too rundown or ugly for market-rate rents? 

Use the advanced function when you get to rental income and input each individual rent.

If fix the pool, I cannot charge additional rent as I am already capped and I will be stuck with maintenance costs and I can't help but think that if someone drowns in a functioning pool and if it turns out that the landlord could have done "something" whatever that "something" is, he may be on the hook for a major lawsuit.

There is always a buyer out there and it just is usually a function of price.

Ultimately, we are full time W2 employees and I operate a high functioning sales team. 

I know Cozy did this, and I'm assuming Apartments.com kept that functionality.

Yield is a function of risk...whether it is in real estate, bonds, dividends, etc.