Here's an article with additional FAQs on cost segregation studies that you may find helpful.

I believe I read not all fixes/repairs will qualify during the cost seg study.

Study the market.

Like Brandon mentioned - you sound like the picture perfect classic "DSCR Loan" borrower - dscr loans are made for exactly this typically - LLC friendly and usually the best fit for when investors hit the 5 or so property mark and hit a roadblock with banks, cash etc like you desribed.Check out this 12-part article series published here on BP on all about DSCR Loans, hope it helps!

One that you know or study a LOT and that makes money:)

I’d personally prefer the one opposite the beach as I think the other lots are too far but I haven’t made a study on hotel clients.

If you want to make the opposite case, look at engineering degrees or point to the wage studies that show on average people with 4 year degrees make a lot more than those who have zero college.  

There have been at least 3 studies that show this is true for virtually every large city in the US (you can internet search this).- buy and hold is currently tough in San Diego.  

I don't have the time to study Bitcoin nor do I have the time or desire to study any individual company thus I invest my traditional retirement savings into low cost index funds.That being said, I do feel like I can study and become educated about my local residential real estate market and it is an interesting topic to me so that is where I spend my time, effort, and excess capital.Regarding, investment vs gambling. 

Quote from @Jamie Hora: The question you pose in the title, "Is a rezone required if availability study can support more density".