i70 is overkill for WP, it is designed around average i55 as the gear it drops.
I often see inexperienced healers not using stoneskin on self, not waiting until target has a solid enmity on all targets, not using eye4eye. Remember you take more damage than the tanker, so if you got a mob on self - dont hurry to self heal, wait until tanker takes it from you (unless you will die from 1 more hit taken). Also use SoS often, i see many new healers forgeting about it.
I often see inexperienced tankers not rotating defensive cds - they should rotate them, no reason not to.