Some other secrets are programs investors can use to save money on downpayments or to buy more properties without having to use income like Non/QM (DSCR or Bank statement programs). 

The new breed of seller financed note buying trainers will teach you enough to find notes for them.

Now I want to sell a handful of LTRs and buy another STR, this time preferably in Florida.

The best way to verify that is call the current agent for the policy and ask them what happens when you buy it - will the carrier still offer a policy?

C properties have no ceiling fans, I will install for $50 if they want to buy it, but it stays at the end of lease, (unfortunately they are usually taken when they leave anyway).  

Or is it more advantageous to keep renting and buy an investment property to rent out instead?

Is it possible to purchase a home from someone, and give them the first right of refusal to buy it back at a specific price at a later date?

Can locals afford to buy a property there for $100k?

My options usually include the all cash/quick close to flip myself, listing it (as an agent) but also offering the seller to do a JV flip together, I could wholesale it, offer to buy it myself for a BRRRR or other long term personal investment, etc. 

Depending on your future lender (assuming you are buying more than just one property) some required multiple years of the business operating before that income can be credited towards your income, others will credit the income the property gets at a discount (70% of the rental take, the day the property was bought.)Now for stuff I don't have personal experience with, yet.1.