I strongly disagree with dropping Fuel the Blood, there’s no sense in having Buzz Axe Bombardier without it. With high Bloodlust stacks and both of those skills, you can one-shot a LOT of enemies, even at OP8 without slag. Hit Release the Beast, pick up a melee kill, then throw those axes! For this reason, Strip the Flesh is also a solid choice.
Fuel the Rampage is also virtually useless if you’re using Release the Beast, and I’d spec out of Blood Trance as Release the Beast is more of a panic button that you want to cycle often rather than something you want to spend a lot of time in. I’d also recommend farming Boll for Fastballs, it’s a short farm and he’s an easy kill, plus he yields decent XP along the way, especially once you hit level 57 as Fastballs often have huge overkill damage and can proc Bloodsplosion chains constantly, just find yourself a consistent slagging weapon and spec a single point into Thrill of the Kill so you can keep healthy while Bloodsplosion does its thing. The Unkempt Harold is farmed near Boll as well and is a very good weapon for Krieg.
Here is what my level 57 Krieg would look like, with a Fastball, Unkempt Harold, and whatever slagging weapon you prefer (Mine is a Slagga) - http://bl2skills.com/psycho.html#50500415050150050104055100000000000