I've got two dps modes I run with. I keep them on two entirely different hotbars so I can switch between as needed.

Hotbar 1 is all about the defense. The only offensive skills there are holy (for AE stun more than damage) and a macro I use. The macro toggles on Cleric stance, casts Aero II, then aero I on the <tt> target, then toggles off Cleric stance. The whole thing takes less time than a holy and almost always works (just have to consider the whole thing one spell)

Hotbar 2 is a different story. I have Cleric Stance manually on that bar, but the only heals I have are Stoneskin, Cure II and regen. To use this bar I stoneskin the tank, toss a regen, activate cleric stance and spend as much of the next 20 seconds targeting mobs and blasting them as I can before I downshift out of cleric stance, heal up the tank, and drop another regen and go back in. The trick here is Stoneskin. I keep that on as much as possible. In fact I often use Swiftcast + stoneskin to keep the uptime and let the regens top them back up. Stone II, a macro that combines Aero II and Aero, Holy are all mainstays.

I have found though, that the true secret to dps as a white mage is actually REPOSE, I said this in another thread, but I'll repeat, "Repose healed 100% of the damage you didn't take" It's situational, but it's THE most powerful tool in the box (IMO) when it comes to doing something other than spam healing. It buys you time, time that you can spend Casting offensive spells, defensive spells, or sticking a finger up your nose and waiting for someone to get smacked in the face. Up to you. But if you're expecting to do white mage damage while CC isn't being implemented you're going to have a really bad day.

For reference, usually when I'm doing this, I'm seeing about 200-250 worth of Aero and about 350-400 per cast of Stone II in mostly strategos and an ifrit weapon in AK. it's a little over 50% of the total dps that my similarly geared blm is capable of (that weapon isn't nearly as good though being a WP drop.) Still, I think that's pretty respectable all things considered.