Wanna hear a joke? Shadow Storm Shot. Just to give you an idea on how many people actually use that and not Nox. As far as traps go, all upgrades but the explosion are needed, explosion is a waste of points. Not a big fan of Razor myself, but it is used by a lot of skinny woman toons.. As for me, I'd go like this:

Aimed 5/5
Nox 5/5
Veil 4/5 ( no explode )
Pierce 3/5 ( unlock, make it hit 3 and health back upgrade )

And your passives would then be

Dex, Str, Int 5/5
Crit 5/5
Damage 3/5 at level 41.

Damage bonus doesn't stack however, it just takes the highest variable. So 3 points in there just in case your pet rotation doesn't include a damage pet. Have fun playin', you chose the best class in my opinion ( played all 3 ).