Q: When I destroy a Keeper with the Laser Sword or Laser Pistol, are attached Creepers also destroyed?

A: Yes, that’s the whole point of the Laser Sword being able to kill Keepers with Creepers on them – that’s one way to get rid of the Creeper. This is true for the Laser Pistol as well, but note that the Laser Pistol is a ranged weapon, and can “kill” Keeper/Creeper combos anywhere on the table, not just in front of you.