Corrected entry: In the scene at the graveyard when the Clown is tell Spawn about his mission and his new body he doesn't teach him how to use it or at least how to put his helmet on to keep his head from getting cut off. Spawn is very important to Satan's plan so wouldn't it be really important for the Clown to teach Spawn.
Corrected entry: Spawn is nearly at point-blank range when he shoots Priest in the head. This should have taken her head off, but instead there is nothing but a tiny hole.
Correction: Actually compared to most movies, this is far more realistic. Bullets don't make body parts and heads explode, nor do they make the victim fly through the air. The small hole is right. It may have done far more extensive damage to the back of her head, but we never see it.
Correction: The Clown wants to lead Hell's army himself, he may have been making it easier to kill Spawn.