Ask if there is a transferable warranty on the pool from the builder. The pool is screened in, so there will be some water loss from evaporation, however from the pictures you posted it looks like the shell is intact and not leaking. If they did not plug the main drain and returns then you know those lines are intact as well. If you can grab a water sample, have it tested and post the results here, we will be able to tell you if any of the numbers are out of whack enough to cause problems.
Problems such as calcium scale and metal staining are unsightly but can be corrected with patience and a little elbow grease. I think you are more likely to run into cosmetic issues than structural ones at this point. If the pool has been unattended for a year it looks to be in pretty good shape.
Since it is a short sale the bank is not likely to pay for an inspection prior to sale. They may allow you to do an inspection at your expense, maybe. If the prior owners knew they were going into foreclosure then they knew they would not be making any repairs to improve saleability once the bank took possession. Banks always sell property "as is".
