1) Two points into Deadly Brew is pretty pointless if you're running Evisc, and if you're running Envenom there's no real reason to not use it over and over. The math gets a bit complicated on which is better (re: different AP scaling, the bonus chance to proc instant poisons for 1 + CP seconds), but what possible reason would there be to ever run 5e/5en? If En is worth using over Ev (and to me it looks like it is, especially at decent AP totals) then just go 5en or 5en/5r and drop the wasted points in Imp. Evisc.
2) Similarly, even on moderate mobility fights there's no real reason to get Fleet Footed. It's faster than AGI + Run Speed or the equivalent in the expansion, but is it faster enough to justify it over another point into Imp. Poisons? I doubt it. It was a no brainer in TBC because a whopping 6 AGI loss for the mobility was nothing, but more Instant Poison procs (read as: 10% of AP plus some more as free damage) are rather nice.
3) Turn the Tables is similarly rather nice, although I can see dumping it for better points. Combo Points means only Muti (plus I guess SS et al), right? Hmm.
If you spam Envenom, I'd say something more like
51/13/7 (points dropped from Cut to the Chase since if you're hitting Envenom constantly you should get refreshes on SnD anyway, but the points could be adjusted). If you do En/R then I think something more like
this. Two points in SnD shouldn't be a requirement if the pattern is Muti, Muti, Finish since you'll be doing that every 12 seconds even with zero bonus energy from Focused Attacks.
I guess I don't really see why you'd ever use En/Evi. Either one is better than the other or it isn't.