It is a C- house in a B Neighborhood.I have run the numbers on an attached spreadsheet.

A well prepared offer in writing will have a lender pre approval letter attached or proof of funds.

Now you have the property - no emotional attachments - no outstanding liens - you get the property free and clear of judgment liens and you are not going to get sued!

Then once approved, I would attach those as exhibits to a contract that says that you will complete the work in accordance with those documents and you will have a mortgage on the house for so many dollars- either the value of the improvements as far as market value of the property, or the actual costs, whichever you and the seller decide, so that if the house doesn't sell and the owner gets the benefit of your improvements, or if they try to sell through another broker, you have your collateral and you can't get screwed out of the money you've invested.

You reference living above the commercial building which sounds confusing unless everything is attached. 

I have attached the link for the property and my analysis.

The unit was almost done save for the bathroom and kitchen, and at that point it was mostly done.I wanted to see if we could move the shower, as it was connected to a claw foot tub and attached to the side of the wall that has a ceiling height of approx 4.5 feet.

I lived in a trailer house that had both size orifices attached to the furnace with instructions on how to change them. 

Plenty of people wholesale houses all the time on houses that have debt attached to them. 

I will try to attach a google maps view of the property to give a visual.