The second villain, "Evil Shirley" who is based on Lauren's mother fires icicles at her foes and her weakness is mud because Lauren's real-life mother is such a compulsive neat-freak. The only way to kill her is to drop a house on her (she's later hit by a motor home).
The Boss's is based on Gus's boss who fired him for working on his video game. His weakness is red ink. Red ink (in the red) signifies losing money. There was nothing his boss hated worse than losing money.