The first pull of mobs you should circle and kite the pack around a little, delaying their auto attacks and of course, get yourself out of the cone AoE attacks the raptors employ.

Not sure when your healer asked you to stay put, probably it's the pull after the first boss, which are all the goblins. They hit generally lighter, so it's okay to stay put. And the reason to stack is because like previously mention, they don't hit that hard, and secondly, the gliders just hit random party member all the time, so your other membres get damaged as well. Stacking will allow your healer, presumably a WHM, to cast Cure 3 effectively.