When I'm on either of my two Favoured Souls in PuGs I use my blue bar to heal. It's there to help me complete the quest, and generally speaking the more people alive the better our chances. (Some exceptions, like the 6 CON Elven Wizard I ran with earlier today, do exist).
But I never start throwing plat at a quest I'm PuGing.
When I'm on one of my 8 non-Favoured Souls, and I'm pugging I don't expect the Cleric, Favoured Soul or Bard to throw plat at the quest either. Once the blue bar is gone, it's gone to me. But I always expect them to heal the party. Though I always prefer it if they'd also beat stuff down in melee, or do some crowd control and throw out some Blade Barriers as well.