The tree looks pretty solid overall (Gunlust+Rampage, pretty typical DPS Sal). However, I would make one change:
ditch All in the Reflexes for 5 Shots or 6.
Why? AitR’s melee damage is wasted, and the reload speed, while nice, isn’t exactly a lot, 5%/skill point. There are better ways to spend your skill points in that tree. 5So6’s effect is quite potent (though locked behind being a kill skill), and moreover, has excellent synergy with Inconceivable. Yes, both effects can happen on the same shot, and when that happens, you get +2 ammo which will be in your gun’s mag too if there’s room (this is what 5So6 really does under the hood: it gives -2 to shot cost, which is normally 1, but can take other values), and the shot cost nothing (this is due to Inconceivable, which sets shot cost to 0, and this is applied before 5So6’s effect when applicable).
Edit: btw, your build is close to what I am going for on my Salvador, which is this: http://bl2skills.com/gunzerker.html#550051551515505015515101000000000