Having a list of the problems made by an expert might make it a little bit easier to make the decision do you want to tear it down or do you want to make it a labor of love and restore it like Grandma had it - maybe with an air conditioning system in it and Hardiboard on the outside, and new windows et cetera...

If so I would strike while the hammer is hot.

Your biggest risk is kids commandeering the thing while mom and dad are in the hot tub,and running over and killing someone(s).  

They kept getting rejected b/c sellers were hearing every night on the news about the blistering hot real estate market that had turned around and they suddenly wanted top dollar for their property, above what comps would justify, even above asking price.

Is the air filter changed? 

Luxury STR's can really perform exceptionally, I've heard St Augustine is a strong market, can't go wrong with anything Naples..Savannah is also a hot spot.

I have a 9 bedroom house, 6 bath with a pool and hot tub. 

I've never had a temperature complaint because our system puts out so much cold air that most people (including myself, who loves AC) are freezing at 72 degrees, because the thermostat is upstairs so the system will come close to running non-stop at 72.

agree with everyone else one thing to have it on a home you live in. but for a rental no way.your tenant expects stuff fixed.. even manufacturers warranties are fairly useless to the landlord.one of my units had a 2 year old water heater crap out.. but by the time you apply for the warranty etc what do you expect your tenants to do go without hot water for weeks ?????

If you offer air conditioning to your renters.