I personally prefer a healer that heals first, but is not afraid to get their hands dirty with the group. DPS for healers is fine in boss fights, before adds, or when running WP/ AK speed runs with FC groups. In PUG's, typically, a few variable come into play.
Is the non- healer DPS good enough to take out the mobs fast enough so minimal heals are needed?
Is the healer geared/ skilled enough so that in the event I take too much damage, they are able to heal me up quickly before I, avoidably, hit my CD's?
Typically, if the group is all relic/ relic +1, and it is agreed upon by the tank and healer, healer DPS is fine.
Just don't let the tank die for the sake of you spamming Holy.
Remember, you are healer first, and a shooter second.