The addon is probably deadly boss mods - not sure if it does anything for 5 mans or just Raids but its very useful for bgs also.

I went back and ran sethekk again the other day and did notice that the initial arcane missiles the boss throws immediately after his AoE do not get absorbed by groundings. For me this didn't cause an issue, I would just immediately chain heal once as he was throwing them, which would bring me back to full. I believe after those initial arcane missiles the groundings will absorb the rest of his casts and if he starts meleeing you, feel free to laugh because he hits like a rabbit (compared to most bosses).

Ok in regards to the questions about the prophets and those cobalt snake-birds....I have 5 shamans so neither was a problem. In regards to the profits 1 LB+CL combo would down them before they even started walking towards me, so I didn't have to worry about that. I think the one pull where there was 2 prophets I used LB+CL on one, then trinket + ele mastery and LB on the second one to insta-gib him.

As far as the snake bird things go, I had no problems with 5 shamans. I'd start at max range, and do a LB+CL, then spam LBs till they were dead. Usually they would get 1 CL off on me but it only took my shamans down to 60-70% life or so. With 1 less DPS it might take a little bit longer but I don't think it should be too bad. If you're extra worried you can always just use your trinket on each pull of those since theres only a few in the whole instance the 1.5min cooldown should be available on each one.

I am looking forward to running this again when my pally is 68 to see how much different it is, of course with 4 level 70 semi-geared shamans and bloodlust it should be super easy.