If you're buying the property for some reason other than cashflow, then maybe ROI and/or COC are important factors to you.Admittedly, I'm a new investor, and a lot of these concepts are foreign to me, but by and large I think you pick a strategy/goal (i.e. cashflow) and evaluate the property in those terms.

I think you have to appeal to people's sense of fairness, although that is a foreign concept to many HOAs.

Can take the concepts to any RE asset classes 

If you are referring to the home warranty maintenance programs where you pay an annual fee and just a flat repair charge no matter what the repair is, I have no experience with these, but they are an intriguing concept.  

I loved the Puget Sound Business Journal but this year they put up a paywall.

You learn about a new concept called forced appreciation, syndication, etc in this thing called apartments.  

I also don't understand the concept of spending $300k cash to get back $1,000/month, less all the cap ex over the years... can you explain why someone would be willing to do that?

The concept is simple.

That leaves the house, which is all paid of, so they own it out right and has three bedrooms, 1 full and 2 half baths, 2 spacious living rooms, and open concept kitchen and a long basement.

Doing deals with little to no money is possible but your going to need to prove out the concept first.