Long story short, I wouldn't worry about including the pre-paid/escrow items as long as you don't forget to bring the money to the closing. :) Disclaimer: While I’m an attorney licensed to practice in PA, I’m not your attorney.

Looking for a great insurance broker who is experienced in handling house-hack situations.We may short-term-rent our primary-residence unit within SF regulations (up to 90 days a year), which we will also want to account for with insurance (been looking through posts here about some insurance companies cancelling people's homeowner's policies when they hear about STR setups so want to make sure we're above board and with a supportive insurance company).  

We have a couple of friends that live down there within walking distance of Sailfish Marina, in fact, we'll be sitting on the peanut island sandbar here shortly...there's no better place to get some quick R&R and take in the "sights" Florida has to offer.

It's generally easier to go from short term rentals to longer term ones but it's not a guarantee.

The rental will likely be short term (6 mo- 1year), so it's a not long commitment, but I still want to make sure I do my due diligence and avoid any potential headaches!

I want to buy/ invest in a vacation property that we can use as a short term rental.

Short answer - if it were me I would self manage and I would have tenants cover utilities. 

Luxery rentals in exclusive resort areas, where short-term renters typically drive up in a Lamborghini and wearing enough diamonds to blind a person v. 3/2/2 brick on slab in a subdivision rented to a blue-collar Joe. 

It was a 130K short sale purchase with 25% down payment but I did some renovations and we got it at a good price so I had some added equity at closing. 

Also, I'm not sure how much equity you think you will have in these properties on the short term.