How scared should I be about DPS?

[Valmaxian]

Snip

I swear you're a mind reader... This is EXACTLY what to do as an AST in dungeons. For me, the healing portion of my group contribution is a very "fix-it-and-forget-it" approach. Each of the three healers has plenty of options to set the tank/group up to survive while you blow things up:

WHM: Regen, Medica II, Asylum, Divine Bennie, Holy stun
SCH: Adlo, Excog, Tether, Sacred Soil, Whispering DAMN, Eye for an Eye (I still use it!)
AST: Bole, Asp. Bennie, Asp. Heli, Collective Unc, Earthly Awesome

The game gives us plenty of options to keep people alive and do other things. Start slow if you're feeling overwhelmed, and don't worry about beating out the DPS. Any damage is helpful. If you find the confidence to rock out the nukes, DO EEEEET!