Those are sweeper movesets, Wobbuffet, so it's not what JDOG's looking for.
I do think, however, that screech should be removed, like you said. It actually lowers the opponent's Defense to make them hit themselves harder from confusion (Without the risk of them hitting you as hard, as the battle drags on).
However, it's still a bad idea, because it gives Muk no form of survivability. Give it Acid Armor for a sharp Defense boost, which will compensate for the Attack boost for your opponent, but still punish themselves heavily.