I first like to short list based on numbers and then deep dive.

We have a potential buyer of a lot in St Augustine, FL who would like to build a new single family short term rental.

I use Proper insurance, unwritten by Lloyds of London, for my STR - covers the extra issues you would expect from an STR like vandalism, alcohol liabilities, business interruption up $10k, hot-tub cooties etc.

We really like it and would like to stay but i don't know if you still intend to keep it now that you're gone.Then go from there.

I think that it is a good long term investment with some serious upside, but don't kid yourself - your car (or your tenant's car) will likely get broken into at some point.

I am seeking an early retirement and it looks like real estate is the way. 

You need sufficient NET (after all expenses) self-employment income from something like contract (1099) work, being a Realtor, wholesaling and so on.

i feel like the local FB groups will not allow me to advertise my STR there because they would label it as "soliciting".. any way to get around this so that it doesn't look like i'm soliciting? 

I have been considering asking to buy the single family in cash to separate the deal but would like that amount to be subtracted from the purchase price while keeping the cash I would spend on the down payment the same to include the single family that way the seller gets the same amount of cash upfront.

It sounds like you have a strong foundation, and getting one-on-one guidance can definitely help you learn more in taking your next step.