"You're right. If Durkon uses Big Heavy Armor against a monster with Bloodlust, and wins, then the result of the shtick (which says that the battle is a draw) means that he actually loses.

In short, don't use shticks that say the battle is a draw against monsters with Bloodlust." - apegamer

There doesn't seem to be any reason that the same shouldn't apply to battling without a shtick since the outcome is the same as one with a draw result.

For the unique rule, I believe that Redcloak is the only multiple unique card. I'd guess that the rule only applies to unique monsters since it would be ok for there to be multiple Kobold Knights in a dungeon but not multiple Nales.