A few thoughts about depth, much of what is restating what is above.
For me, I go down to 8', but don't have a diving board. I like to tread water, just dive in from the side, etc. As I am over 6 feet tall, I need a 7 or 8 foot deep end. Depth of 6 foot or less would restrict me from what I like to do.
The other thing that I will do in the pool, is just hang out and talk with people. And for that, I am typically sitting or squatting in the shallow end (3.5 foot depth for me). If I had gone with 4 feet, I think that would be too deep for me to sit/squat in and keep my head easily above water. I don't walk in the 3.5 foot range, so the belly height issue is not a thing for me.
I don't play volleyball or basketball in my pool competitively, so the need for a sport pool for fairness does not apply.
The social aspect of the shallow end is a big deal, as people will congregate there. I believe that a typical 8 foot diving well takes up 24.5 feet, so if you went with a 33 foot pool and 8 foot depth, what leaves a very small shallow area for people to hang out in. Mix in a couple kids on rafts with a could of standing adults, and the shallow end would already be full.
If it were me, and I was length restricted, I would probably make my shallow end (3.5 feet) 12-14 feet in length. I would then just gradually get deeper until I had at least 7 feet of depth on the deep end. (and I am not sure what slope that equates to and if it is safe/allowed)
Not related to depth, but One thing that I think people need to think about with their pool is hardscape/landscape/grass layout.
Make sure that you leave room to move around, and plant stuff that wont pollute your pool with leaves/pollen where possible.
If you are going to be cutting your grass on your own (rather than paying a service to do it for you), make sure that you leave easy paths to push your mower. This may seem silly, or not important, but if you leave small triangles in a corner, or leave an island of grass, you will curse yourself every time you deal with it when you mow.