I figure i have enough to worry about on my team. Let my opponent worry about his. If they don't state and effect occurs (like a team ability or optional power), then it's fair game. This makes them think about the game and not rely on me telling them how. Sometimes as a player i remember their abilities, sometimes not.. Sometimes they may actually want to ignore and optional power/ability. If i never tell an opponent how to play the game (and apply the rules) then i dont see any conflict. If it's a new player, i will. If it's an old hand, tough. I'll tell em after the game to help them maybe in the future.

It becomes cheating when you knowingly ignore a game effect. If you forget about the poison, it is fair game. If you say in your head, "hopefully he will forget" then it becomes unfair and cheap. It might not necissarily be cheating, but it is dishonest and wrong.

On abilities like outwit, prob control, and perplex, it is good strategy to not remind your opponant.