Charred dagger will last a pretty long time.. its very good.. and they get better...
Slashing is great too... slashing is quick damage.. but you wont be stealing much health if any at low lvls.. IMO.. you should raise Piercing and slashing.. keep them pretty even.. like raise one to 5 then another to 5 and so on.. That way if theres a better weapon for piercing at lvl 5 then y ou can get that.. but if theres a better slashing at 11 then you can get that.. or w/e

Keep your options open =]