More of a definite PVE build, the main point of this build is to continuously use skills. The relentless backpack will heal you very quickly, and the determined on the third slot of the weapon (actual weapon doesn't matter much), will help you keep those skills up.
In cases where you're fighting a boss or more difficult enemies, swap to the markman's rifle to up the skills with cool headed. If you need to pick up faster on the healing, swap to the shotty and let your skills do the killing. You'll proc the predatory on skill kills as well.
Feel free to swap out critical save with strike back, and use those sodas & waters, since they'll help as well.