Not really an expert here, but I do have a lvl 84 SK in hc ( though now in Hell is really slow, levelling an alt Wiz for now), so I'll share my build...
Skills : I put 20 pts in Gasping Frenzy ( really nice, best when you're on low life, it'll kill mobs very quickly ), Death Strike ( the bleed bonus was insane before, now it's mediocre but the skils does nice dmg and heals you a bit) Heat Blood ( nice DoT, the added dmg is good) and working towards Shadow Vortex ( that's because I'm in hc, in normal I probably wouldn't take it...).
Tried the pet perk, but it didn't make a noticeable difference, so I respecced out of it. Took Cold Shield, not that great but slows down mobs at lvl 20, that's not bad at all!
Stats: I reccomend using the highest dmg 2H ( for Gasping Frenzy) so Attack Haste is good to have; then look also for some Casting Haste, and go for +Str , +Dex for max Chanche to Hit(95%) - but remember to also look for Res and -Status Duration, expecially in hc.
Combat: I usually stun a mob first, then cast dots ( look for the icos, the 2 dots you have have different duration) and the enfeeble/vortex spell and attack with Gasping Frenzy/ Death Strike. Heal when needed, but if you can, hit with Gasping Frenzy first - as I said, the skill is great at low life. When a mob is about to die/fleeing, throw a dot or Gasping Frenzy and pull another one(Frenzy hits a second target if the first dies). In Hell I hardly chain, but in normal/nightmare that's less an issue...
That's all I can think of now, if something else comes to mind I'll post again. Hope it helps
