If you feel like giving a custom kernel a try, Cubed kernel has 'sweep to wake' enabled where you slide your finger left to right across the soft keys to wake, and right to left to sleep.
Works great not having to use any buttons to wake/sleep. The kernel is still in beta, so some of the governors don't work quite right, and once every few days you might get a random reboot. For me, no big deal, I love sweep to wake. It was one of things I was really missing switching from the GNex.
As for volume wake, I haven't played with it, but UKB ROM does have the option when setting things up in Aroma. Whether it works better or worse than the flashable zip, I couldn't tell you.
