Scallop
Pros: Makes bends/vibratos easier
Cons: The heaviness of your finger's touch effects the notes (as in heavy touch would create a #, too light touch would create a b)

Pieces: I assume you're talking about necks. 5 pieces are more stronger, thus creating a better tuning stability and neck strength. The differences between 3 and 5 piece necks are normally negligible.

Coil Tap: Makes a humbucking pickup able to achieve single coil sounds/tones.

About the trem, not too sure what you're asking. Hope that helps.