1 Apr 2008
If the creature is no longer on the battlefield when the ability resolves, you may still perform the action if you want.
1 Apr 2008
Peacekeeper’s ability doesn’t cause the combat phase or the declare attackers step to be skipped.
1 Apr 2008
When the ability resolves, you choose whether to sacrifice the creature or perform the other action. If you can’t perform the other action, then you must sacrifice the creature.