Some post-commentary, now that I'm not completely exhausted. It was pretty late last night when I got done... never did figure out how to wear berserker armor... I didn't try that hard, though. I do suspect how to go around it, and may try again (with another run). If I find it, but it seems to show up more often for me than dragonslayer.
The butcher's cleaver saved my life. Thirty of those runs? Almost all of them deaths trying to do that run. And I found the cleaver twice in the process. The first ten levels or so are completely brutal on UV, and you have to terribly abuse cornering and luring enemies with item drops... or using their new pathing, which really helps. Imps will now chase you AROUND a wall if they see you, which allows you to smash their face in. Nearer the end of the game I stuck to malek's armor since it's the only thing that wouldn't dissolve off of me in a few seconds.. and abusing juggler to get free kills. A number of times where I was quite threatened by death, due to (nightmare) anachrotrons (they did 2-7 damage per hit) and masses of arch-viles + insert other here. The arch-viles did decent damage, the other beasties would knock me backward. Barons weren't dangerous when I met them-they act fast enough... I actually had more problems with fireballs from imps.
I have to say that using malicious knives and a fire-resistant armor makes it quite fun to wade into a group of mancubi spamming rockets and laughing as the hits only do 1 point of damage to you. Very satisfying.
I also found the napalm launcher four times, an assault shotgun, and a laser rifle. What the hell, RNG? Pretty sure there were more, but after a certain point mancubi would just blast half the level.
Nightmare cacodemons are nonthreatening. I have never found them, in any run, to actually be dangerous. More tedious than anything. Maybe if it was a nightmare run of something without too many levels...