For what it's worth, I still can't kill the first boss here on Heroic, even with lots of 359 gear. I'm sure it's just a skill deficiency on my part. It just seems to take me ages to do the 2 levers and my resto shaman can't keep up with the healing. I end up almost dead on all 5 toons by the time I'm back up top after clicking levers and I just can't spread out again, interrupt boss, avoid blue flame, etc... fast enough.
I have a holy priest for healing, but back when the team was weak, I switched the ele shaman to resto for double healing, and it works. Killing is slower but HP is gained back faster, and the fight becomes less stressful.