Jonmar, just so you know, I too have a Hayward sand filter, and yes, it really will remove the dirt. Every time you vacuum, you stir up the sediment, so the water will look murky for a while, but then will start to clear again through filtering and settling.
Also, re diverting water...my pool is at the bottom of a three-tiered terrace that's at the foot of a hill that leads into a forest. At one point in time it was actually a storm basin. The builder, who we tracked down (BC it was a foreclosure) had constructed a perimeter French drain around the concrete and topped with stone. The drains tie into another French drain on either side of our house that continue downhill. Not sure what options are available to you with site conditions, but if you have a way to keep the water moving away (as opposed to filtering downward, creating pressure under your liner) that might b a good option. Do you know if when constructed a sump was built under your deep end, and if so, was it tied into you pump system?