So, I went through the entire thread and I can't believe no has bought this up:
How are you getting the full damage from AB when you refresh it ~3 seconds afterwards on your backstab? The DoT ticks every 1 second for 6 seconds so at best (assuming lag and whatnot) you are getting ~66% of its damage.
Anyways, I don't personally use that "best case" opener. Chances are, wasting half your acid blade DoT to get a backstab in will NOT kill the target, so I prefer to go
AB+HS>Shiv>Stim boost if not up (off-GCD) > Corrosive Dart> Lacerate> Sever Tendon(root for 2 seconds talented)
from this point, If I am still in melee range (people tend to want to move right after they get out of the stun. The root stops them, and they are slow to react) I will drop a backstab+AB (very easy to get behind someone; If you can't, practice!). If I get knocked away, I will cleanse the root (YES, you can do this for most roots/slows!), use Rifle Shot to stay in the higher energy regen area, get back into melee, or use an explosive probe to finish someone off if they are below 20%. If I get stunned, I either trinket, or just eat it.
Of course, PvP is all about adapting to the situation at hand, so the most important thing is understanding what all your skills do, and being able to follow a logical flow, prioritizing skills depending on either their burst, their efficiency or some other fact relevant to the fight at hand.
Anyways, I am more of a PvE'r than PvP. I think the Hidden Strike nerf was needed in both cases (although the filling the resolve bar thing is BAD) However, the ArPen nerf was not. AFAIK, Operatives are NOT top dps, so nerfing their PvE dps to assauge the fears of the masses is NOT the way to go.