But, in a market where short-term rentals in areas like Tampa Bay are on the rise... and I mean, last time I chatted with an investor-focused agent down there, she mentioned neighborhoods around St.

If you can put 20% down, why are you mentioning FHA?

Happy to make intros at any of those I mentioned if it'll help.

As is was mentioned above Fannie/Freddie require 12 months before you can use the new value to walk away with cash.

In case of continue the deal I would request and appraisal and inspection but still, as you mention, not sure if it is a good deal.  

If your goal is growth, a refi now might make most sense, but only you can make that decision.I'll also second what @Jaycee Greene mentioned that most lenders won't go to 80% LTV on a cash out refinance. 

Depends on the state but it ranges from $800-1500+ and, as Chris mentioned, we have the borrower pay for out of the gross proceeds of the loan.

I am part of BGNF (what @Jeff Brown mentioned above) and the preferred return is there every month.

As mentioned, I would definitely seek out the advice of experts in those specific markets depending on where you decide to go. 

Realistically, many properties that go to auction may be in such bad shape that they don't justify the high bidding amounts, leading to losses as I mention above.