I think the only thing they should change is to make shriek not 1-shot non-tanks if they are in decent gear. Insta-kills are horrible, you generally don't get to practice anymore once you eat one, and it places a lot of stress on new healers in particular since if they die it's a wipe. Bringing you down to really low hp is enough of a "hey you should pay attention" without making an attempt a complete wipe and still puts you at risk to die to other attacks if you aren't taken care of immediately.