Krieg was designed as the “bad guy” to begin with, and each of his trees fit a dif type of bandit:
Bloodlust: Marauder with rifle gamestyle
Hellborn: Pyro Lunatic / Flamelauncher dudes
Mania: Badass Psycho Mutant.
So yes, you can go Hellborn without BXR (but i personnaly love melee igniting enemies lol).
Bloodlust is heavily oriented as a support to his action skill (Taste of Blood, Fuel the Blood, Blood Trance and Boiling Blood).
As for Mania, it is by definition the tree which makes him a monster at melee with risks for it.
Yes, Krieg self-hits himself when meleeing with Silence the Voices, but it is a skill which allows you to one-hit split in half most mobs in the game, and bosses in a couple more swings, so YES it needs drawbacks!
Apart from that, Krieg is what he is. A pscho. No crouching behind cover, no shield skills, no Axton vibes.
As an overall opinion, i think everyone needs to keep the idea of balance to skill trees and characters. The patches and hard work are not here to overpower all characters lmao.
Each char has its playstyle so it’s not like we should flatten them all to “dps boost, shield boost, hp boost”.
Also awesome work to Mr. Lord of Patches hands down