You need 3/3
Death Rune Mastery.
NEED. Read below after I go through the rest of the talents.
Rune Tap, see below.
Vendetta, ditch it. It's useless for DPS. The only time your DPS really matters is on a boss fight. Likely you wont be getting many killing blows in a boss fight. So it's a waste of talent points.
Mark of Blood, see below.
Hysteria is great added dps. You want this. When you use Dancing leprechaun use Hysteria first, the bonus DPS is significant.
Sudden Doom is what makes the Dark Death glyph worth it. You want as much free added dps as you can get from your Heartstrikes.
Blood-Caked Blades is better point for point than Outbreak is by a fair margin. Plague Strike is not a huge DPS % for blood. Specifically the upfront dps value of it, the DOT doesn't get the bonus from outbreak or the glyph. Which is why you want Glyph of
Dark Death, not Plague Strike.
I recommend a
51/0/20 build. (if you want rune tap for some reason, you can always shift a point from Imp Blood Presence).
Heartstrike is your main ability to use. It's the best DPS you have for a single rune. Bloodboil is very good DPS as well on AE, it just doesn't do very much DPS until you have a disease on everything and more than one blood rune to use it after a Pestilence.
So your priority should be
1) use both your diseases and keep them up, refreshing right before their last tick.
2) use death strike to create death runes
3) use as many of your global cooldowns on heartstrike as possible, just don't forget diseases
4) RP vent deathcoils if you have a spare moment, don't use all your RP, deathstrike gets a % bonus from RP
5) when a bloodlust/heroism is used use hysteria and Dancing leprechaun, perform like usual.
It works best for blood.
I shy away from Rune Tap and Mark of Blood in favor of Improved Blood Presence for a couple of reasons;
1) is that they require a blood rune to use, lowering DPS.
2) is that they require a global cooldown to use, lowering dps.
3) while you may want to think your healing abilities are gonna help keep you alive during fights. Often they will not. Your healers will do that for you, if it is needed on a fight.
4) Improved Blood Presence is passive.