@Jennifer Lee Yes, I know it's like all the air has been expelled from a balloon.....you feel deflated.Anyway, it's good to share your grief and that will strengthen your confidence in moving on.You certainly learned a lot from this experience and will no doubt use it in future deals.

That's a breath of fresh air in America today!

@Jeremy Krantz  the streets do get water in them now with high tides and its why all the houses we are currently building are 4 to 9 feet in the air  LOL...

We are a HUD authorized Brokerage in Central Florida that suports investors.It sounds like you are well under way, but if there is any way we can assist, you just need to ask...

They host a general meeting for all of Central Florida once a month as well as county specific meet-upshttps://www.cfri.net/

Central Air?

I looked on a few different HVAC web sites and I don't see parts listed except for  thermostats and complete electric baseboards.If hydronic, then yes, but you'd have to know how to drain the boiler, solder heating element to pipes, and refill/bleed all the air out.  

Your vinyl tiles will let air leakage happen between each joint. 

The run also must not be too long; our code says no more than 25 feet.Here's some specifics from the International Association of Certified Home Inspectors:The recommendations outlined below reflect International Residential Code (IRC) SECTION M1502 CLOTHES DRYER EXHAUST guidelines:M1502.5 Duct construction.Exhaust ducts shall be constructed of minimum 0.016-inch-thick (0.4 mm) rigid metal ducts, having smooth interior surfaces, with joints running in the direction of air flow.

Or the ones that come in looking at my low cost rental asking where the dishwasher, garbage disposal, central air, walk in closets are, but literally "lucky to have 2 rocks rubbing together in their pockets" here in Connecticut.