Exploding doors

[FlawlessHappiness]

Where exactly did you put AddUseItemCallback("", "Completed", "cheryl", "Boom", true);


These:
SetEntityActive("cheryl", false);
SetEntityActive("cherylBroken", true);
PlaySoundAtEntity("", "06_break_wood.snt", "cheryl", 0, false);

can be replaced by this:
SetPropHealth("cheryl", 0);


Also you have a typo here: RemoveItem("Complete");
It should be: RemoveItem("Completed");