You will have a very hard time buying an existing location without paying above 1.5 times the cost of building.4. 

Or get a line of credit on existing property, use it as the down payment for another property-100% financed.

Using owner occupied mortgages would allow you to purchase with a lower down payment, but to use it a few times would require you to move to not commit mortgage fraud. 

It sounds like there is something that already exists that you're describing that is similar to Pacaso but different.

Many will say this isn't possible in this market, while it is not as easy as it once was to find these opportunities, they still do exist.

Gotta wrap my head around how to manage it from in Oregon.That's why my company exists!

Generally replacing only flooring does not require a permit unless you have to replace or repair underlayment.When you get your permit, be sure to keep those photos showing that this addition has been in existence since long before you ever bought the house. 

What you describe - a multi-unity where you can rent out one side and live in the other - does exist.

Do these issues exist in the Columbus, Cleveland and Indianappolis markets? 

Because there are existing trees, trying to work them into the entrances and landscapes.