I couldn't agree more on the 3d touch, fantastic. Very innovative solution to a problem that drove me crazy! Now can you point me to the iPad that has this feature? They come out with a fantastic piece of tech and they fragment their ecosystem to only give so much on an upgrade cycle.
I'd also love to see 3D Touch on iPad but I can understand why they'd delay it on iPad.
iPad with 3D Touch would be thicker and heavier which isn't something most people would want. If I can notice the weight difference between a 6 and 6S, I'm sure it would make a much bigger difference on the iPad.
There's also the cost issue. Apple probably decided that adding an expensive component over a larger surface area in a much cheaper device didn't make financial sense for them.
BTW, on iPad, you can use two fingers on the keyboard to turn it into a trackpad... so much better than editing text with the magnifying glass.