We're kind of op.
This is anecdotal i'll admit, but I'm guessing your estimates are anecdotal as well, but so far i've never seen another class that can put out the damage I do as madness, unless they're significantly outgearing me, except for maybe ops but there are hardly any operatives on my server. I am definitely not out dpsed by any marauders, assasins, marauders, or mercenaries
Everything i'm doing is either instant or channeled, except for heals / cyclone. Madness has a 30% proc chance meaning just about every full lightning channel I get a free cast. Not to mention our slow (which does damage btw), affliction, and creeping darkness are all instant.
Armor really does not do THAT much in this game, I'm not sure on this but It only seems like medium armor is a 5-10% reduction compared to light.
However, I can say that you are vastly underplaying the bubble, assuming you go into fights with your bubble already up it's incredibly beneficial and I would say makes us one of the most survivable classes, under the right circumstances. And as a dps, we SHOULDN'T be as survivable as a tank, that we're close is somewhat absurd.
Not to mention we have some of the best kiting abilities in the game between force sprint on a low cd, our instant slow, and our knock-back.