These details and the creative aspect of an STR seem like they will be an exciting avenue. 

Raising equity can be the most challenging aspect of closing a deal.

So I almost “broken even” with the cost of construction vs. valuation aspect.

The old adage is true in real estate as other aspects of life - if it seems to good to be true it probably is. 

Just walk away if you sense they won't let you investigate any aspect of the property you wish to.

Finding some sort of value-add aspect or buying at a discount means you either create or walk into equity, which protects you.

• Resources for Learning: We’re working on improving our deal analysis skills and would love recommendations for tools, books, courses, or calculators tailored for beginners.• Networking and Connections: Are there local Bay Area meetups or forums for new investors?

This is correct, so I would disclose every aspect of the sub to and how it relates to the seller, perhaps going so far as to insisting the seller sign off on an acknowledgment that he understands the ramifications.  

Focus on the physical aspect of physical assets. 

If it is the right investment, focus on how you can negotiate the best terms or tailor your offer to the situation.