36 year old gunite pool - help!

I'm seriously considering buying a house with a 36 year old gunite in-ground pool. The pool is cracked from the waterline all the way to the bottom. The owner claims that the pool doesn't leak, but based on the water / sewer bills, I don't believe it.

I actually don't want a pool, but finding a nice house in SW Florida without one is difficult. My dream would be if the pool and all of the equipment would disappear, and the existing deck would extend to fill the space. However, if I drain the pool but leave it intact, I think that I could find some acceptable creative uses for the space. However, I have some concerns:
(1) the empty pool could pop out of the ground. There is a lake outside the house that is 5 feet lower than the bottom of the pool, so I don't see how the groundwater could ever get high enough to float the pool. However, I'm not an expert on these matters.
(2) What happens to a gunite pool that sits empty over many years? Does the pool become even more damaged than it already is? If I ever need to sell the house, will I just have to sell the pool 'as is' with a huge discount on the price?

If any experts have any advice, it would be much appreciated!
Thanks!