I had the place under contract and everything was lining up well until it was getting dewinterized yesterday for the inspection and they discovered the pipes underneath had been removed.

I obviously don't want an unhappy tenant living underneath me, but they already rejected the offer.

And the mold underneath is kinda scary.Schluter makes some awesome products and the Kerdi membrane system is one I like a lot.

It may or may not look good depending on what is underneath.  

i would have to assume your local soils are full of clay, requiring a fully grouted wall.Miami Dade as well as the rest of Florida follows the Florida Building Code, which is based on IBC & IRC.

You never know what you'll find underneath the texture.

It is exposed to the elements and is just soil?

What I have heard so far is that I could insulate in between the floor joists and use a thicker underlayment underneath laminate flooring in order to achieve noise reduction from above.

Your survey company is supposed to give a topographic survey telling you what the current elevation of the ground is, and then an engineer is to test your soil to tell you what you're building on.

As for contingencies, it would depend on the lot, the location, are there any soils reports or anything that have been done on the property yet?