Greeting's MMO Champion peoples, and hopefully fellow Witch Doctors!

I am currently level 41, playing nightmare on Act two with some friends. My Girlfriend and I blitzed through Normal and Act 1 of Nightmare but kinda hit a snare in Act 2. As such we enlisted the aid of our friends (they are only 30-35 in levels) and realized we still had no luck. We're usually running either 1 WD, 1 Wizard, 1 Dh and 1 Barb or 2 Barbs, 1 Wizard and 1 WD. As such, we decided to farm some gear up in Nightmare from the Butcher since it's 3-4 pieces of gear and 30k exp for turning in the quest at the end. While doing that, I realized the potential of a purely support Witch Doctor and I wanted to see ideas and suggestions from you guys.

Skills:
1. Hex; Rune that heals periodically.

This should be a no-brainer. Pull a group of mobs? Not only do you take one mob out of the equation, he takes 10% more damage and its a periodic heal (at our level, 617 healing) which helps if somebody takes a hit or two. This is actually really great on bosses when we have a defensive oriented character and the slight healing helps keep him topped off.

2. Int Gainer; Rune that heals you.

Again, anyone who plays a WD knows this is just the stupidest ability in the game. Easily doubles my Intelligence and heals me for 700 damage per enemy hit. While I'm not pumping damage out, I am trying to keep some poisons on the boss and I'm auto-attacking with my darts so the damage boost is just insane.

3. Acid Drop; Rune that keep the Acid on the ground for 6 more seconds.

This ability surprised me because when I initially got it it was terrible. However, with a good weapon (and a socketed Red gem for the damage boost), the initial damage and the Dot damage is great especially while kiting. Turn around, hit somebody with your Int ability to heal and gain damage, toss down a poison and keep running. On big groups its obviously better but even on bosses, this damage with the poison DoT is still a decent amount of damage at the start.

4. Big Bad Voodo; Rune that increases the duration.

For groups, this is a GREAT skill. Eventually I'd like to get the rune that increases attack damage as well but I do not have it right now. With this skill down (and with my fetish army down), the damage output of our Barbs/DH goes up exponentially. It's a great thing to pop early and a great end to a boss when people are starting to go down and you're nuking the boss. The movement works great for bosses like the Butcher where his charge and the fire grates are a bit unforgiving if you don't move quick enough.

Left Click. Poison Dart; Rune that restores mana or slows the enemy.

This is obvious. The auto attack ability for Witch Doctor does good damage, drops a dot on an enemy and is great for solo kiting. If needed, switch the runes around to either regen mana or slow the enemy. Not much else to say about this tbh.

Right Click. Fetish Army/Mass confusion; Rune that reduces CD on Fetish Army or reduces CD on Confusion.

This ability switches for bosses obviously. Confusion doesn't help with the bosses (unless there's adds) so I usually switch it out for Fetish Army. Army provides a decent damage boost and can buy some time by tanking some damage if your tank goes down and he needs a rez. Confusion is great for bosses with Adds since those adds then turn on the boss and you usually get them down with some AoE anyway.

Passive Skills:

Now these are where I sort of... fall off as I DONT know what I want 100%. Currently I use:

Jungle Fortitude
Spirit Vessel
Spiritual Attunement.

Spirit Vessel is obvious; you died? Nah you're good, immunity for 3 secs to pop that potions and you're back in.
Jungle Fortitude I feel really helps out with a lot of the AoE damage that's unavoidable later (Jailed/Frozen mobs come to mind). Overall though I don't feel to attached to it especially with Spirit Vessel allowing a free rez every 90 seconds.
Spiritual Attunement is the skill I'm unsure of now that I'm not to damage oriented. Essentially what I wanted to find out from people on here is does Bad Medicine work with bosses and work with ANY poison? For instance, if i dropped Acid Rain on somebody, their damage would be reduced for 9 seconds by 20% (6 second duration on the acid pool, 3 second duration at the end). With the skill being essentially spammable, could I basically keep a bosses damage reduced permanently by 20%? This would be the one skill that I would definitely consider adding in if it works.

Anyone, suggestions are greatly appreciated! Does anyone know if a more Int based build is worth it here or maybe go more vitality for survivability? Right now I'm currently stacking Int/Vit and keeping a random amount of other stats (especially Dex with the dodge on it).

Thanks again guys and critique away =)