I read books year after year, including Rich Dad, Poor Dad, all of Tom's books, etc etc, and I discussed investments with friends and family in finance regularly throughout my life (have a PhD, love this stuff), and despite all of this it has still been mediocre results given my goal of retiring before I'm too old to enjoy it. 

This was poor advice.

It also comes with a restaurant that hasn’t been in service for 40 years, but the structure is in surprisingly good shape.Here’s what I’m thinking through so far:Standard due diligence: +Phase 1 and 2 environmental, city plans/zoning, health department approvals for bringing the restaurant back online.Talking to the Army Corps of Engineers and the local harbormaster about dredging (not something I’d do immediately but want to know long-term outlook) and figure out generic cost for budgeting purposes. 

Always pick a provider experienced in STRs.Depreciation recapture: When you sell, you’ll face recapture tax on accelerated depreciation—this is real, so factor it into your hold/exit strategy.Too aggressive underwriting: Don’t assume tax benefits solve poor property fundamentals.

Ideally Health & Safety or Rents & Profits in CA, TX, AZ, NV.Thanks in advance!

Even my mistakes and sometimes poor decisions have not been bad enough to result in any disasters . . . yet.

Opting for cheap properties means you get stuck with cheap problems - lower tenant class, lower rate of appreciation, tougher outsale, constant maintenance due to poor treatment, chasing down rents, more personal time invested managing etc. 

Incredibly poor business deal. 

I think these are poorly trained tenants ...

I'd start with house hacking. id read set for life and rich dad poor dad to start.