I very much like the idea of quests, the adventures with an additional condition that makes them optionally harder. And I have an idea for a new quests condition I think would work well: Only use gear with common rarity, so no uncommons, rares, epics, or legendaries. I remember that "commons only" was very popular in some circles of Magic the Gathering players, as it avoids the "you only won because of your expensive cards" problem.
Great idea, I'd have to say. Less hard than drawback only, but still viable - as the quest difficulties seem to vary anyway (1 health, being the hardest).
