skrump

I know this topic has been covered in this forum previously, but seeing as every installation is different, I figured I'd see if you guys have any advice for me! I'm shopping for a new pool pump. The primary reason here is for the energy savings. I live in California, and currently have an ancient Anthony 2 HP pool pump that was there when I bought the house. I'm getting beat up pretty bad on the monthly electric bill, so I figured I'd go for a 2-speed energy efficient model. I've done as much research as I can online first, and I think I'm on the right track here, but I did have a few questions. To fill in the background first, here's my setup- 17200 gallon pool, plus 650 gallon attached Jacuzzi. 2" pipe, at least where it's visible coming in and out of the pump/filter. 3 intakes (spa, pool drain, skimmer), 2 main returns (pool) + multiple smaller spa returns. Pentair FNS Plus 48 DE Filter I downloaded and worked through the Hayward pump sizing worksheet, and from that I figure I have a Total dynamic head of approx. 40 ft. Here's my questions: 1. After working through that Hayward worksheet, there was one thing that threw me for a loop. According to the worksheet, the 2" pipe that my pool is plumbed with should only be able to handle a maximum flow of 84 GPM on the suction side, and 105 GPM on the return side. Looking at the performace charts for 1.5 Hp pumps, in high mode...Those should be putting out around 120 GPM, correct? And currently I have an old 2 Hp motor installed, which I assume would be pushing an even higher flow rate. Doesn't this mean I should be blowing out all the plumbing in my system? Obviously I'm not, but I am confused on that one... 2. I've pretty much settled on a 1.5 Hp pump... I'd like to retain enough push to have strong jacuzzi jets, but then be able to shift into low mode for day to day pool circulation. I'm looking at 2 pump models right now- The Hayward Super II and the Pentair Whisperflo. Both 1.5 Hp, both dual speed. Best price I'm seeing online for the Hayward is $474, best price for the Pentair $630. Quite a premium for the Pentair, but I did see mentioned in these forums that the Pentair is the more energy efficient of the two, so I may come out saving money in the long run on that one. Any thoughts one way or another? 3. In the comments left for one of the previous pump question threads, the point was raised that most 2 speed pumps don't come with a method pre-installed of switching between high and low modes. Does this apply to the Pentair and Hayward pumps? If so, seems like a pretty bone-headed design. I haven't seen much online addressing fixes for this... Would I have to install a switch to toggle the intake voltages(????)....What is the workaround for this? Thanks in advance for any advice!!!