I was quoted $400 a month average for oil deliveries during the winter months and a additional delivery maybe two to keep the hot water going during the warm season.

That is the exact model that I use.  

Some HOA's are run by power hungry non professionals and can ruin your business model.  

These are all things you can back-of-the-napkin model on a spreadsheet.

Very interesting model.

When I built a spreadsheet projection to model/replicate what he'd accomplished, I think he turned $80k cash into $3 million of equity in 5 years....and I got really excited.

Once you do this, you can model different scenarios for selling in different years (taking into consideration rent increases, expense increases, capex, appreciation, and debt paydown) to determine when you have the best IRR. 

I think it can be a great way to invest but it's not as easy as it seems and the cash flow model does not FIT everyone's goals.I want to outline in detail my 3 most recent out of state purchases in 2016 and show how they better meet my goals.

Mine is a beautiful 2004 higher end model that was well over $100k new.  

Although it may seem like a good idea because of the interest you are getting, I think staging it too far off your current business model.