1. Dumb or they know the tank and he she tends to rush out of there. Mp is not a problem, we are just standing at the start.
2. Depends on content. Doing it is a good thing if the healer dps' s on normal dungeon. A good healer knows how to manage mp and dps. Rather than heal and stand there.
3. Dumb, if what you said is correct. Rez cost a lot if his\her mana was below a certain point. Ya if the fight is easy probably. Was waiting for swift cast. Cuz it wasn't a big deal. Or the person panicked. ..