I have tried to build it around some survivability coming from Spirit Walk with its heal and the massive slow from Grasp of the Dead while maintaining a high amount of AoE damage and kiting ability.
The way I currently play it is like this:
I start by spirit walking through the mob pack and dropping the Soul Harvest on them midway. When I come out of Spirit Walk I drop Grasp of the Dead just in front of the pack followed by Wall of Zombies Pile On. After this I spam Zombie Bears and carry on rotating slows and damage spells as needed, using Spirit Walk to escape/heal and grab Health Globes.
At 4.2k damage I'm doing 22k damage with 60k crits from Pile On, and 9k damage with 12k crits from each Zombie Bear. I use Poison Dart to fill in the gaps for around 3k damage a hit.
It works quite nicely in that it slows quite a bit but keeps some nice damage, and I don't find myself dying too much with it. I'm able to kill bosses with a slight modification to the spec depending on the fight.