With regard to the anti-seize, most references say that if the plug threads are nickel-coated (shiny silver) and the head is aluminum, you should not use lubricant on the threads. Lots of folks do anyway. I generally do. It will not interfere with the current flow. Graphite-based anti-seize is conductive.
If you use lube, be careful not to over-tighten the plugs. At a given torque setting, the lube will make the plug pull harder on the threads in the aluminum head. You need only enough torque to crush the washer (which you can feel on a new plug).