The contractor and two of his workers were working on the main floor when three men approached and knocked on the front door.

I've actually been digesting the Beginner's guide with great interest, and have a good first draft of my business plan and approach.  

My dad approached me and wants to invest.

You are lucky she is showing her true colors now when you can potentially do something about it as opposed to when she has already moved in.The "I try to help people out" approach to rental real estate rarely works. 

How should I approach this lead with a reasonable offer?

How should I approach this lead with a reasonable offer?

Being a Dave Ramsey ELP, I usually approach these situations from that perspective.

You're spot on with that approach, but determining the outcome (accurately factoring in the profit potential and required time) clearly involves some significant experience - not the kind of thing I should attempt to plan for.

The homeowner was unable to make mortgage payments to the estate for over a period more than 24 month by the time she approached me as a mortgage broker for help.  

I want to take a pragmatic and calculative approach and get my education first, but at the same time I'm looking for properties CONSTANTLY.