All brand new Heating and A/C for a house that size would cost $3-5k for me if there was no need for new duct work.

Not sure if that is feasible, but you might want to price it out to see if makes sense to start fresh and not have to worry about cloth wiring, etc.  

I have no idea what the previous tenants did to mess this up (microwave was brand new when they moved in) but I ended up having to throw away the appliance and replace it (took it out of the security deposit and didn't hear any complaints, so chances are they knew the "present" they left behind....)

If by healthy you mean personal health, we are getting a Fresh Market and a new Kroger Marketplace, along with having a couple great local places like Hendersonville Produce and the farmer's market during the summer - people are wanting more and more healthier options here so it is slowly but surely happening in Hendersonville.  

If you are unfamiliar with design features in this price point in your coastal area of FL, might I suggest you hire a consultant or designer (make sure the designer is an investor at at minimum, investor experienced as many designers love to pick expensive name brand stuff that you could easily make the same look at half the price).Hattie's list is good and outdoor kitchens are a must in coastal areas like yours and mine.

Nothing like ripping off brand new drywall to add insulation.) 

The most recent upgrade question I've gotten is due to their dog ripping out brand new carpet in the upstairs.

@Wes Brand I won't argue with you.  

and i agree completely with @Mana Silva that rehab presents (for me) too many unknowns inside those walls whereas, once i'm outta the ground on a new build, i KNOW everything is in brand new condition and placed in working order (and can of course sell it for more).  

Some people don't like certain brands, while others love them.