I think I have something that may fill the bill for a pickup wiring quick connector system. I was playing around with various small connectors for PC innards, and came up with what you see in the photos below. The female connector is easy--any of a number of PC connectors will work; I used a 4-wire CD drive output connector for that. The trick is to have male connectors that will be small enough to run through the pickup wire channels in the guitar body. For that purpose, I cut up a male cooling fan connector, so that I could get just the wires and pins soldered to their ends. I covered the excess part of the pin with heatshrink, and--voila!--male plugs that are practically no bigger than the wire diameter. Insert them in the female plug and you have a nice, snug connection. So these just need to be spliced into the pickup/switch wiring and I should be good to go.