The screws in question are a large diameter but short length Phillips ( utterly useless compared with that great Canadian invention - the square Robertson head screw ) Before you go for the gusto with a plasma cutter, I would centre a drill bit of the same diameter as the top of the screw head at the cross of the Phillips screw. Drill out the heads of the screws with someone taking the weight of the door. Remove the door. The stubs of the screws which are still in the car will be easier to attack with Release All, wd 40 and heat. Use progressively larger drill bits to drill out the shafts of the screws. When you have drilled out as much as you can and have softened up the brute with some solvents, try using a reverse thread screw extractor to remove the remains of the screw. Tedious work, yes but beats using the plasma cutter. You will need some very high quality drill bits to do this. The titanium ones are good but don't fall for the Chinese titanium plated ones. They are junk. Good luck with the project. Dan (MY72BUG) in Goderich
I'd rather have a partial bottle in front of me than a partial frontal lobotomy.