If the holes filled with oil, the four plug hole o-rings on the valve cover need to be replaced. That will stop the oil leak.

Otherwise, your problem seems to be a good excuse for new pugs and wires Check to see if the electrode on the top of the plug broke off into the plug wire, that would make it not stick on and requires plug replacement. This has happened on both my Civic and RX-7, the Civic did it spontaniously while the RX-7's plug came apart while I was trying to remove the wires.