Completed the repair. Here are my findings (hopefully to assist others):
1. The coil pack had been previously replaced; however, the broken plastic nipples on the coil pack did not correspond to the most fouled spark plugs.
2. Cylinder #1 was the worst - the old plug was completely black. The others just looked worn down, but not with black soot all over. This cylinder also had a broken spark plug boot when removed.
3. All spark plug wires were replaced (not with OEM wires, but an equivalent high-quality NGK wire set).
4. Anti-seize lubricant was applied to the plug threads, and a torque wrench was used to tighten the plugs to 20 ft-lbs.
5. All engine codes were cleared upon starting the engine.
6. During the first minute, there were still mis-fires heard; however, after the car was taken for a quick test drive, the operation and power returned to normal.
7. No additional P03XX codes appeared after a re-scan.
8. Problem appears to be solved for now.