My buddy on the other hand, follows my advice and reinvests the returns to the point where the cash flow is so excessive that a roof, furnace, foundation issues etc, doesn't even put a dent in his wallet.

I believe transparency and integrity are the foundations of any good business, and it's refreshing to see others are aligned with that mindset and practice as well.

Looks like a rubble type foundation wall.

Any other books you would recommend to someone completely new to real estate investing but who would like to build a solid foundation going forward?

Your top-notch experiences and resume will provide you with a strong foundation in real estate investing. 

(Foundation, etc)4) Black mold, asbestos, lead paint, other other costly repairs. 5) It need significant cosmetic repairs where the purchase price just isn't worth it. 6) They may have an odd layout of the rooms. 7) Non-compliant septic.8) Trouble with permits or tenants9) Listing agent has a poor or incorrect listing.

Does anyone have information if placing it on a permanent foundation will make sense from a long-term value standpoint?

The foundation was already approved, permitted and finaled years ago for a 3400 sf house, and its solid and I won't be building directly on the overhang edge; but rather back away from the edge a few feet to prevent any load issues all the weight will be on the longer sides of the existing footing.

It sounds like you’ve built a strong foundation, and now it’s time to make that money work for you. 

You have built a great foundation to work from.