Mold, termites, cracked slab..oh my

[RBH B.]

My father has a 4 bd/2 ba 1950's ranch that he has owned and lived in since the 70's- it is paid off. The home was remodeled ( poorly) in the mid 70's. Now, fast forward 30 years with the basic just getting by home maintenace, termites in the studs, windows falling out, black mold in the ac vents, the brick is literally falling off of the sides of the house- which leads us to believe that there is a cracked slab.

I am at a loss of what to do. Do we even attempt rehab, or do we just tear it all down and place in a new home, eventually this will more than likely be a rental. The homes in the area max out at $140,000 the home is currently taxed at 100,000, but, I think once they see it, it will definitly be assessed lower.

Q1. My thoughts are to get in an appraisor, inspector or structural engineer, or do we do all 3?
Q2. Are there a list of qualified contractors/appraisors/inspectors available that I may reference?
Q3. I am thinking of using a HELOC on the house for the repair/demo and paying that off with rental income. Has anyone had experience with this area before?

Thank you for your time, experience and advice!