I think cooldowns might be a way to introduce interesting new traps, like player attack/defense/cloak boosts. Then have a second effect that disallows you from setting the trap for a certain amount of time, so you could go death blossom or to plaid for an hour but would have to wait a significant amount of time before it could be active again. Also since trap effects can't be removed, it might bring a new strategy to defense other than total passivity.