I would just stop going there instead trying to track down the owners and analyzing their corporate structure.  

When you write up your profit and loss statement, how do you break down the mortgage?

I am getting quoted 8.25% interest on a duplex with conventional loan and 25% down.

Unless you are terribly priced, or have a severely limited customer pool, turning people down is going to be part of the business. 

We were happy because we bought around 40 houses with only about 5% down out of our pocket in the end.They didn't cashflow very well for a few years because we had to get higher leverage to get all of their money back but rents are going up and they're doing better now plus we have a ton of equity that we can repurpose if we so choose.

Even better if I can sit down with a builder and get started on funding and blueprints.This meta-strategy will use all the above strategies:1. house hacking: house will be built from scratch to maximize rent/room, while having a family unit/ADU for my family to live in one year2. costseg/STR: the building will be built from scratch to maximize bonus depreciation.

He asked the right questions and I could tell he was serious, so I decided to team up with him, and we purchased this run down three flat, and gut renovated the bottom unit, while increasing the rent on the top two units.

I'm trying to wrap my head around the water and sewer setup for a tiny home community.

Recently several of my investor clients have leveraged equity in their primary or investment properties as down payments for purchase acquisitions by obtaining a HELOC or fixed rate second mortgage. 

The "right decision" really comes down to what YOUR goals were when buying this property.