The sellers had put so much pots, plants, planters and shrubs out that I thought there were too many plants/planters that would require a new owner to upkeep.After a few potential buyer tours/showings, the owner heard all the comments (via the security cameras) about how there was a "lot going on with the plants and stuff out front".

I see people without capital no experience or capital being taught to “help” desperate homeowners by tying up their property in a contract they have no way to successfully close without finding someone to pay more; costing the homeowner behind on their mortgage payments to lose valuable time that can easily lead to foreclosure; I see a program taught to students to take over a property ‘subject to”, leaving the seller unable to qualify for further mortgage financing, responsible for a loan secured by a property he no longer owns, and all held together by someone with 0 experience, limited or no capital, and no liability.  

Well, I wouldn’t go that far, people throw that word around too much these days but I would say they made a lot of promises that they haven’t kept and paint a very unrealistic picture with an extremely high pressure sales scheme that does a disservice to the vast majority of their students.

Security systems are easily outsmarted, that’s the point of the initial visit, to case the joint. 

Exterior security cameras.

Consider using an FHA loan to secure a 1–4 unit property with just 3.5% down and take advantage of tax benefits by living there for at least two years.

They never eat any cost for their poor communication they find a way to throw it off on us or the tenant. 

The area has certain advantages like shelter from regulation risk (pretty much as low as anywhere in the country if you buy in the approved STR tourist zones) and long term security (people aren't going to stop going to Orlando anytime soon). 

I know that the general guidance is that emergency funds aren't to be invested, but given our financial security and the fact that we already have a personal e-fund in a safe, non-volatile location, would it still be crazy/unwise to invest this 15k in an S&P500 index fund in a brokerage? 

Loan Security: The property will serve as collateral for the seller-financed loan.