For example can a parrell humbucker be eq'd to sound like a single coil? Or even can it be eq'd to the other possible wiring's, series etc.
You can emulate various tonal characteristics, yes, but pickups have differences that aren't just tonal, so not able to be emulated with an EQ.
These include phase differences, sustain and decay, interference, the differences between parallel and serial wiring etc.
If you want to be able to emulate different guitars, so you don't need to carry many with you on tour, the closest seems to be the Line 6 Variax series, which some people love, and others hate. It provides emulation of entire guitar and amp setups, including pickups, necks, bodies etc.