Similarly charged magnets will repel each other, opposites attract. I would think that the magnetic charge on your pickups wouldn't be strong enough to affect your playing. I don't know if it would alter the sound or not, probably throw some static in there. Sounds like it would be a worthwhile experiment if you could find a magnet to use as a pick.

I don't think it would mess up the charge on your pickups, it would take a serious electrostatic charge to demagnetize the poles.

Let me know if you ever give it a shot and get interesting results.