Originally Posted by
Eisenhower
When you're doing progression raiding a healer will usually need to DPS, but it depends on when you start doing that kind of raiding. If you're hitting the content on release there's no way around it. The party gear level just won't be high enough to compensate for the lack of experience in dealing with mechanics, leading to weak performance against DPS checks. If you start during a catch-up patch or later, the party might be geared enough for healers to be lazy.
It might be differing mentalities, but I say don't worry about mana. Go in hard on healing and on dealing damage if it means seeing more of the fight and experiencing more of the mechanics. It only becomes a problem if you're wiping because of an empty mana pool. Besides, as a WHM you have plenty of ways to conserve and replenish mana - and in a critical situation you can wail on the bard or machinist.