Some additional WD feedback, using this build to help tweak efficiency:
Witch Doctor - Game Guide - Diablo III
When you create a build, there is always a good use of those skills and passives chosen. What I mean here specifically is when you use the skills at the right times, leverage the synergies and utilize appropriate sequences of skills you can end up with a drastically different result. The WD is one of those toons where the more technique and knowledge you have, you can "squeeze" out more effective damage and defense.
Some details of this:
BATS BUILD BOT LOGIC SUGGESTIONS
* Bats increases damage output over 5 seconds. This means that the most damage output is deal when bats have been consistently channeling for
at least 5 seconds.
* Hex/Jinx can be used while channeling bats
and does NOT interrupt channeling. This gives an additional 20% damage.
* Soul Harvest/Vengeful spirit gives a 650 INT bonus for 30 seconds
and does NOT interrupt channeling (at least 5 enemies within 16 yards, easy with mob density). This also gives 65AR of course.
* Spirit Walk/Honored Guest gives 30% mana bonus
and does NOT interrupt channeling. This is helpful for RD packs and also to help return huge mana losses caused by restarting bats because of knockback, vortex, AOE etc
Pause there for a second, so this highlights some of the differences with damage output based on how the skills are used and the timing of when they are used.
* Locust Swarm/Pestilence is a WDs "super generator". It will draw mobs in directly at the WD which (1) Gives the enemies to continue channeling the bats for that "minimum 5 seconds" (2) Gives enough enemies for soul harvest to hit at least 5 enemies for max buff (3) Allows super mana generation due to grave injustice (
make sure your WD has at LEAST 14 pickup radius!!) (4) One of the best reasons, it will also reset the cooldowns on your skills also due to grave injustice (
make sure your WD has at LEAST 14 pickup radius!!)
Pause here again, so you now get the idea of the synergies created here. We already know that Soul Harvest, Hex and Spirit walk can all be used while channeling bats without interruption so if we throw in the fact that all these mobs are going to reduce the cooldowns from the grave injustice skill, we now also have the ability to
SPAM THESE SKILLS OVER AND OVER while channeling in large mobs

That's where the vengeful spirit rune really shines.
SKILLS
* Grave injustice - resets cool downs, gains mana, gains life.. Godly (don't forget that pickup radius

)
* Gruesome feast - Crazy damage and defense too!
* Spiritual Attunement - Synergy with max mana on Zuni helm (and SOJ and TOTD and other max mana mojos) results in more regen also
Ok so that's the reason for that build (yes there are many other good ones also).
PRIORITY
Firebomb/Ghost bomb - Here is where the last skill comes into play I didn't mention yet, it is because this is really only for "if things get rough". This skill allows instant damage (not over time) to a large radius. The damage isn't that great, but when you have a large pack the damage adds up due to the radius. The biggest key here is that there is almost NO mana costs associated. All the other skills use mana and in the event the bot gets into a jam and doesn't have any mana left, it needs something to use to get out of that jam.
I have noticed that the WD doesn't "realize" how to prioritize these skills and to only use ghost bomb when mana is low. It also tends to channel bats for like 1 second, throw a bunch of ghost bombs, channel bats another second and throw more ghost bombs when there is plently of mana remaining.
Hopefully this is good feedback and the type of details folks are looking for.
Thanks!