http://www.wegame.com/watch/fall-of-...ing-legion-eu/
Maybe this will help, we got only one hunter in raid and he manages to do all things he needs to - decent dps on boss/adds + dispelling enrage from Shambling. Just put focus on shambling and when you see enrage icon on his portrait, use macro /target Shambling Horror /cast dispell.
On phase 3 i think you should use best aoe you got, dont know hunter class very well (volley?). If you got DK,Mage and Lock in raid you should have no problem with taking down vile spirits - dk can use IT/PS on boss and then pestilence on adds - its main aim is not to do dmg but to put Ebon Plague on them to increase greatly dps of your casters, but damage from diseases will also help ofcourse. Mage can respec to fire and do imba dps on spirits (living bomb) and Lock, well one of best aoe in game, my group done it with only 2 ranged dps once and they managed without bigger problems.
Tbh, LK is very easy now with 10% dmg buff. ;p