I just completed the second half of MSV on LFR and there are a couple of things you should probably warn your group of since most people still haven't seen the fights.
Spirit Kings: For Qiang the Merciless (the first guy) make sure the raid is stacked on your tank for the entire phase. Stay with your tank when he moves to dodge flanking orders.
Elegon: After the sparks hit the pillars, THE PLATFORM WILL STILL DISAPPEAR and the raid must move to the outer ring.
The Elegon one is going to kill the most people.