Re: Hum cancelling question.
Everything's fine, you just don't have the two coils you want. First, find out which coils you have by tapping them with an allen wrench or something. Then decide which coils you actually want.
The push/pull cuts the humbuckers by shorting the coil junction to ground, right? Well instead of going to ground, one of the coil junctions has to go to hot. But not the main hot on the switch or volume pot. It has to return to the hot of the pickup itself. Then you'll have the "other coil" of that pickup. So be mindful which coils you want, and then switch the appropriate wire.
If, after the mod you don't have the right coil locations, you can always flip a pickup around to move the active coil to the other side, too.