In PAX East QA Yoshi said that healers need to remember they're still healers and their first priority is keeping their party members alive ("Don't get wrapped up in cleric stance so that all your party members end up dead" or something). It's from this video from around 28 mins: https://www.twitch.tv/videos/127955803.
Basically he said the same thing everyone else has been saying: keep your party members alive, then you can DPS. :)
