As for your encounter with the Reaver, I've also encountered the same situation on my Reaver while facing Wardens and Lore Masters. A Reaver catching a Burg out of stealth and meleeing toe to toe should own a Burg, don't you think? Besides, you didn't mention if he actually got a KB on you or did you hips?
The point being, Creeps are hardly OP in general and we all can point to instances where one or the other are OP. At your own admission you beat a Warg (your counterpart) who has full audacity every match. That seems to be unbalanced in favor of the Burg if all things are considered.
A Burg like a Warg should have to pick their fights and shouldn't be able to stand toe to toe with a melee class while the same Reaver should be able to out melee a LM and should be at least able to hold their own with a Warden.
So yes, it isn't balanced but I would hardly say (generally speaking) that Creeps are all OP...
PS: and thank goodness that freeps can't simply roll a fully equipped character for the Moors, otherwise we'd have 48 EZ-mode Wardens running around..