This is mainly based on my testing in SPVP.
hey i've been looking over your build and have a few suggestions, i am by no means a pro having only played a few weekends and stress tests, so theres my disclaimer.
First and foremost i would remove the staff as my secondary. I find that the staff needs preparation to be most effective and since you are looking to an offensive condition build this isn't necessary. I would replace it with the axe warhorn combo for fast direct damage and also the ability to give yourself swiftness or daze the foes you are facing. Stacking bleed to around 10 or more then switching to this combo, dazing and using ghastly claws is amazing.
Secondly the traits need a bit of work. Starting with spite, you only are using one signet so the 15 seconds off plague signet seems that it would be much better utilized elsewhere, Reapers might or spitefull spirit seem like the logical place to head. Which ever you decided to take with the first trait i would take the second since we arent using the staff anymore(in this theory, but also why would you devote an entire trait to your secondary weapon?).
Curses next, i would take weakening shroud over master of corruption as well as withering precision over lingering curses. The reasoning behind this is you want to maximize the amount of conditions on your foe to lessen the chance that your bleeds will be dispelled by a single remove effect such as the ele's stop drop and roll trait. Mass removal effects will still give you a hard time, but this can be some what countered by having the direct damage available from the axe in your second weapon set.
Next your points in soul reaping. First 15 point are exactly what i would do, but i'm slightly confused by putting the next five there as well, I would put either 5 point into blood magic for the regen at the start of fights or into spite simply for the 5% condition duration.
Utilities, i wouldn't use epidemic as in structured pvp its far too rare that enough people will be clustered enough to warrant it's use. If your speccing for condition damage you will be far better off using plague instead on lich, as lich generally benefits more from power, which you wont be stacking in a condition build. Corrupt Boon is fine if your find yourself against many guardians, rangers, or thiefs but personally i find well of power much more useful. Also dont disregard spectral walk if you are running a somewhat squishy build, you can cancel the skill and just use it for swiftness or you can port back, both very useful.
sigils, you will probably want to use the 60% on crit to apply bleed with the 10% bleed duration, off hand i prefer to use the chance to chill.
Runes TBH im completely unsure if i should use the multiple 2 set bonuses to stack bleeding duration as long as possible or just go for strait condition damage. More testing needs to be done.
http://www.gw2build.com/builds/simu....317.319.327.0.0.0.0.0.0.362.0.0.25.30.0.0.15
this is basically what i'm thinking of running on my necro, any tips or critiques would be appreciated
*edited for spelling and formatting*