The real problem however is if you miss your dps streamer, you're uh, shat outta luck...

We need to do heavy damage and lots of it alongside potential double critical hits. Yay for critical double hits! Let's combo up shall we?
9+1+3 Critical Strikes
11+1 Dagger Mastery
rest+1 deadly arts
Black Mantis Thrust
Repeating Strike
Twisting Fangs
Locust's Fury {E}
Critical Eye
Siphon Speed
Expose Defenses
Plague Touch / Res Signet
12*2=24% double striking + 20% Locust = 44% double Striking. This really jumps your attack speed better than frenzy ever could. Every other swing is nearly a 2x attack and its chance to critical?
13% Critical Stat + 6% critical eye + 17.4% 12 dagger mastery = 36.4% Critical striking.
The 44% double damage chance is still quite sexy regardless... But I'd like to see how much chance of doing a double critical is...

With BMT, you have your double snare which makes it very hard for them to escape. Under Locust's Fury {E}, your dps should end up in the sky somewhere with constant crits + double attacks overflowing from your blades. With Zealous Daggers, and 13 Criticals, you should be able to empty your entire e. bar into them and use Twisting Fangs as your finishing blow when your energy dips to 10e.
Your only self - heal is Plague Touch but if you're getting attacked by enemies, then it's time to just twisting fangs and run the hell outta there... Expose Defenses works well with your smash them down dps to last for quite a bit before running for the hills. The idea is to just barrage them with unblockable repeating strikes until they go down or your hexes wear off.
The high energy regen from your double crits and zealous and 13 critical strikes should easily offset any energy issues you may have.
I think with the 13 expertise mechanic applied to a 13 critical assassin, this makes the assassin the ranger equivalent of a melee magic type...