So - the 15% vacancy you refer to is economic + physical?

Keep in mind I haven't physically inspected the property was built in the 70s 

I attended a training seminar recently where they beat into us "structure drives behavior!"

Depending on how you are structuring your lease option deals it can be considered "Brokering without a license".  

I do have the money to pay off the note of $30,000, which I believe I will need to do, because of the job situation and due to some physical limitations keeping me from working right now.

I currently work as an executive in the IT field and my fiancé works as a project manager in construction building skyscrapers and other urban structures.

You should find out from your local building department if they will accept what is known as standard construction plans or if you will be required to have them produced by a licensed architect and licensed structural engineer.Usually if your city will approve your proposal the electrical and gas meters will be installed , after your inspections have been approved.

I didn't see any issues structurally or anything.

I have a quick question on the deal structure.

I would definitely recommend that you consider your $50k as operating capital and structure your deals to use as little capital as necessary to acquire and stabilize a property with the intent of pulling whatever capital is invested out of the property as soon as it is stabilized.