Hello and welcome to my DK guide for private servers.
First for the OP damage.
Its easy, just put Rune of Lichbane ( Rune of Lichbane - Thottbot: World of Warcraft ) on your weapon/weapons and spam Icy Touch ( Icy Touch - Thottbot: World of Warcraft ), Plague Strike (Plague Strike - Thottbot: World of Warcraft ) and then Blood Strike (Blood Strike - Thottbot: World of Warcraft )
Now the OP healing (yes, healing)
First spec Vampiric Blood ( Vampiric Blood - Thottbot: World of Warcraft ) in blood talents, also spec Rune Tap ( Rune Tap - Thottbot: World of Warcraft ), Improved Rune Tap is most likley bugged on your server too, so skip that, now, if you have malls, buy a Fel Healthstone ( Fel Healthstone - Thottbot: World of Warcraft ) and some Argent Healing Potions ( Argent Healing Potion - Thottbot: World of Warcraft ), now when you figth and got low HP, use Vapiric Blood, then the Healthstone, Rune Tap and the Healing Potion, for me, the Healthstone heals for around 9k, the Potion for around 4k and Rune Tap around 2,5k. Thats 15,5 K!
Thats it for today, if this is a repost, just tell me, and if you have something to add, just post it here ^^
/Imbecill