I am pretty sure all modded weapons and other gear have been officially canned. Anything that was made by an editor, but is still considered legit by the game (i.e, an Explosive Norfleet) will exist, but anything absurd like an Infinity Nukem will be gone forever.
On another note: I've been easily decimating the waves of Overpower, although an issue that I am having sometimes is getting someone slagged while still trying to stay alive. For that, I swapped out the Slagga for a Slagged Kitten. It may have a lower elemental chance but given the healing effect I can keep bombarding them with bullets. I should also note that the instant you go in there the difficulty is set as if you had 4 players, much like what Hyperius/Master Gee do, so that will make things much, much harder. If damage is unimportant (which is not the case most of the time), I swap out my Alkaline Bee Shield for an Evolution Shield. The Overpower gives it a bigger, more significant health boost, allowing for much more health and so much more tanking. Although, I would prefer a Neogenator, as it has a higher health bonus and elemental resistance.
I have also been playing as my Assassin, and I find the Pitchfork to be incredibly powerful with him, especially Slag variants. It has a Night prefix, so crit damage is boosted %120, making headshots absurdly deadly, if you throw in the Bee Shield damage as well. The only issue is flying enemies. Rakk, Surveyors...they can prove to be more than just cannon fodder, and are even deadlier if they are of the Badass rank. I find them excruciatingly annoying, however finding a tight confined tunnel would easily solve that, as they would either get stuck or just fly around pointlessly. That or use a Norfleet on those pesky buggers. B0re is very helpful for taking down BUL and PWR Loaders, a Corrosive or Slag Pitchfork chewing through them like nothing.
I find Kreig's strategy and skills to be...hypocritical. Considering many things, your goal in UVHM is to kill everything as fast as humanly possible and live through it. His skills are based on taking/giving punishment, and when your target dies, the pain stops. Even if they are tough and are just, tanking it all, you pretty much just stand right in front of their faces, with their stupid aimbot hitting you nearly everytime, absolutely showering them with blaster bolts and bullets that only chip away at their health or do too much damage to stack Bloodlust/Elemental Elation. There should at least be some more movement speed bonuses, and maybe even a slag upgrade for thrown Buzz axes, because when you start going berserk you have no way of weakening your enemy. Oh! Let's not forget that with some weapons can literally hold your entire ammo capacity (sometimes even more) which makes unloading on enemies highly costly. I also wish they would make it so Explosive damage would get it's own stack system, and maybe the more stacks you get the bigger the blast radius/damage/critical damage, and maybe to tie in with the Hellborn tree, make it so all Non-Elemental/Explosive weapons have a random chance of inflicting the other four elements.
I have not played as the Siren, Commando, or Mechromancer for a while, but I plan on it once I get my Assassin up to Level 72.