I run Kara with my guild every week for a full clear. All bosses were easy other than shade and he was simple once I figured out a strat. Did ZA this week with the guild for a full clear. Dragonhawk and last boss were the toughest just because I was noobing things up.

Shade - I set up in the doorway. Have a tank on Shade in the middle so he doesn't move around.

Fire Wreath - Nuke like Crazy
Arcane explosion - Spam follow and walk toward the closest wall - move all shamans forward so they are touching the wall at the end - most the time I'm in line with the door so I just walk into the opening
Blizzard - this was the tricky one - look at where its at - if there is a question move to the center and don't cast. Evaluate. Move out of the center to a spot behind the blizzard and follow it back around to the door burning him down while you do it. Then stay put.

40% - Anytime you would have been burning him - burn water elementals instead - I pop fire elementals here normally - it is great if you can have him hit 40% during a fire wreath so you can just sit there and target/burn water elementals

ZA

Dragonhawk - Is tougher to stay out of the orbs than with a single player. But can be done. Other than that standard.

Last Boss - Phase 1,2 - Tank and Spank
Phase 3 - I dropped searing totems and earth elementals. Then I set up on a side all the way against the wall with the shamans spread out against the wall. I would chain heal anytime one would take damage from a tornado. Then I just waited for our 2 melee dps, the totems and elementals to get him to 40%.
Phase 4 - Burn and heal if a sham got claw swiped
Phase 5 - Burn burn burn move burn burn burn move - stay out of the columns of fire