You can use a laser level or even a water level to ascertain if and how much the pool is out of level--which it should not be. A water level is easy to make--a long piece of clear plastic tubing--3/8" to 1/2" will do fine. Just fill it with water and with a helper, hold the water level in the tube even with the measuring point at the end you think is high, and see how much it measures off at the end you think is low. 1/2" should be the maximum.

If they are simple surface cracks, well, I guess that's probably normal.