try my build http://gw2skills.net...GbNuak1ssYgxkAA
the blind thief
blind may not seem that impressive as it stops ONE incoming attack, yet blind can affect multiple targets which could all be looking at you! and with the trait Cloaked in Shadow everytime you stealth you blind nearby foes. this is incredibly useful becuase what is a players first reaciton to a thief coming out of stealth? either CC them or burst them down, this makes that first reaction in vain!
The damage traits are furious retaliation (fury for 15 seconds when target reaches 50% hp) and power of inertia if you want it (gain might when you dodge), i find it optional but useful
things like pain response and instinctual response are AMAZING as they are automatic and can be lifesavers on there own.
concealed defeat im sure is optional, i like it, but i can see people taking enough points out it and putting it somewhere else (hard to catch is something ive been eyeing)
the build is much more methodical then traditional backstab builds as your "protection" from damage (dodges, blinds, stealth) have to be paced apart because of the revealed debuff that lasts about 2-3 seconds.
once you get used to it your target wont have more then 1.5 seconds to really do anything to you at any one time, and i find the damage more then sufficient to down enemies before i run out of initiative/stealth.
again let me just say, HIGHLY survivable, with decent damage, not instagibe damage, but good damage