Relax. You're swinging after the bell.
I'll go over it one more time.
Since you can't get the crank gear off, then removing the motor plate is the next best thing. To do this, those flat head screws can be troublesome sometimes. If you don't have an impact screwdriver, then take the largest blade screwdriver that fits in the screw head, make sure the screwdriver has a square shaft, and get a large adjustable cresent wrench. Get into a position that alows you to put all your force directly through the screwdriver and use the cresent wrench to turn the screw. If this doesn't work the first time, try heating it up and tapping on the screw, then try again. If all else fails, drill or grind off the screw heads and let the machine shop deal with it later. You could let the shop remove the gear also if you still can't pull it after the plate is off and the crankshaft is removed.
All of my factory shop manuals show this gear with 2 tapped holes. All the replacements that I've seen are untapped. It's cheaper to make that way. Somebody has tinkered with your engine before, apparently.
