Ohhh...I thought you meant you were leaving a sump pump in under the liner/vermiculite. Luckily, I don't have a groundwater issue, so as long as it doesnt rain, it is dry as a bone down there.
I was torn. The pool I grew up in was 5'6" (5'2" water depth) deep end. My parents moved, and put in a new pool, and it is 6' (5'8" water depth) deep. I am 5'7" and wifey if 5'1". Pool I grew up in, I could stand on tiptoe and wander the deep end, which I liked, and we never had any issues hitting bottom when jumping or even shallow diving. The 6' pool, no chance, on tiptoe Im still an inch or so shorter than water depth, however, it is fun jumping in and swimming to the bottom. I am not sure if it is really much different in that respect or if it is the darker liner on the new pool that gives it a "deeper" feeling. She has a dark liner on new pool, and while you can see the bottom in full sunlight, it just looks really deep...kinda that whole "you can't see the bottom, must be deep". The old pool had a standard 1990s liner, and there was no "mystique".
As it sits, right now I can hit 5'8" depth (5'4" water depth) deep end with no rock demo. We are also planning on a mid-range liner, not light and not dark, so Im kinda getting the average of the two worlds (depth and liner color), which is fine by me. If I stick with this depth, then all my numbers for the slopes work out well, so I think Im just going to call it good. We are members of our community pool, and they have a 10' deep end with a 1 meter board, so I figure if we want to dive, we will go there.