Wow! What an opportunity!
Keep the pool for rainwater catchment. Fill it with fish and duck weed. It will probably help control tempature inside the greenhouse.
Turn the frame over the pool onto an actual floor, it needs major reenforcement for that.
Plant In 5 gallon buckets stuck in holes in floor, or cover the floor in something
water proof. Either way pour the fertilized water from your pool/
pond into the growing pots by hand. This will filter the water and fertilize the plants.
To really filter the water you will want a large Aquaponics grow bed along the wooden wall.
The only downside I see is that you are in Florida. Does anyone in Florida actually need an extended growing season or a a way to irrigate?
I am ignorant of actual growing conditions there.
I know pests,slugs in particular can be an issue. I don't know if a greenhouse will help with that, but I would not tear it down, no matter what.
There are just too many uses for a building like that, and you can always garden in there. It could even be a shade structure!
Another thing is using the pool as a coolth reservoir, running warm air through pipes sunk into the depths to cool it off.
Good luck, I hope you keep coming back for more crazy ideas !