It sounds like you've got some good strategies there. In AoB, you're generally going to take more damage than in games with ranged weapons, so anything you can do to minimize that is good. Use doors and corners as much as you can so you can get to point-blank range before they get a shot off. Sometimes, if I see an enemy approaching the doorway from the wrong angle and it looks like he'll get a shot at me, I close the door, move on to the other side of it, and open it again so that he's coming at me around a blind corner or I'll take an extra step away from the doorway to a "knight's move" position from it and then take a step toward him when he sticks his head in the doorway. (This means he'll still melee hit you first, but at least he won't get a shot at you) Or if you can't do any of that, take advantage of running and move in zig-zag patterns to dodge as much of their fire as you can.
Use your starting armour for gift-dropping. Once it's down to the last five percent or so, it's much more useful for that purpose than as actual armour. Five points of damage protection isn't worth the reduction in running speed and you can keep using it for that after all your med-packs are gone.
Personally, I favour going for Berserker before Brute 3 because the appeal of occasional berserk power is pretty great. :) Come to think of it, I've never actually tried getting Brute 3 before Berserker, so I can't really say how they compare strategywise.
Unless you're going for the Gargulec Cross, I suggest leaving most of the enemies alive and just heading straight to the stairs. Try to get to Chained Court as quickly as possible, then make those berserk packs last as long as possible, getting as many kills as you can to level you up to your Master Trait if you can. Obviously, reaching Vampyre trait is a huge boon that makes the rest of the game easier, but you might want to consider playing as Scout for the stair sense so you can get to Chained Court faster.
One more idea:
Move up to Nightmare difficulty so you get the benefit of longer berserk and extra health from small healing items! :D
EDIT: Also, all this talk of UV AoB makes me feel like making another Gargulec Cross attempt, something I haven't tried in a while. :)