If I use Palafin's "Justice Kick" attack after I move it up to replace a Pokemon that was KO'd by an opponent's attack, does it do anything?
No, Palafin was moved to the Active Spot during the opponent's turn, not during "this turn".
Justice Kick




×2
Jet PunchThis attack also does 30 damage to 1 of your opponent's Benched Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)

Justice KickIf this Pokémon didn't move from the Bench to the Active Spot this turn, this attack does nothing.
This Pokémon’s ancient genes have awakened. It is now so extraordinarily strong that it can easily lift a cruise ship with one fin.
If I use Palafin's "Justice Kick" attack after I move it up to replace a Pokemon that was KO'd by an opponent's attack, does it do anything?
No, Palafin was moved to the Active Spot during the opponent's turn, not during "this turn".