Update on mine,
Cause of failure: low oil pressure, valve to piston contact on cylinders 1 & 3, and torn head gasket on cylinders 1 & 2 (this is likely what caused the spark plug to get stuck).
Upon disassembly the tech noted heavy scoring on the cylinder walls in cylinder 2. Cylinder 1 was heavily covered in carbon build up. Cylinders 1 & 3 have small indentations in the piston from when the valves hit the pistons. I have NO idea how that happned, I have never "money shifted" my car, however I have let friends borrow the car for extended periods of time so perhaps it was one of them. He also told me that coolant was leaking into cylinder 2 and a little into cylinder 1 because of a torn head gasket, likely damaged at the time of building the engine, it just got worse over time. I have photos, just have to get them uploaded to a hosting service.
As of today Ford has authorized a complete longblock replacement. The technician is trying to get them to replace the turbocharger as well due to metal shavings in the oil system.