Ignition switch, keep the wd40 going through it, ya got nothing to loose at this point in the game.
Oil filter, as you have buggered it by putting a screwdriver through it a ripping the thing to bejesus. The last resort would be remove the exhaust, to allow good access to the facing rim of the filter, know heres the trick, to get a drift, like a small headed cold chisel, on to that rim, don't go crazy and score the face that the filter beds onto.
Also don't be afraid to hit in the direction of tightening up, for this often helps in releasing.
Also now that the headers are remove try using the strap as well as the drift, if there is a spare pair of hands around.....
Just another reason for spending a couple of extra hard earned dollars, on K&N filters with the nut on the front.