Staff Elementalist has been a staple party member in dungeons pretty much since day 1. Since the nerf to ice bow, the DPS has obviously taken a hit, but I doubt that the elementalist is liable to be replaced any time soon.
Most dungeon groups will always say “Zerk or bust.” It’s got the best damage output, bar none. That’s just math. And they’re right. As far as healing goes in your water attunement, it covers enough to not need investment into Healing Power, allowing you to branch into more damage stat setups to help with damage output.
If you’re not confident in your ability to stay alive using any slotted cantrips and dodges, then you’re only left with the option to adopt some more defensive stats; Soldier’s or Valkyries stats are probably the best alternative, both offering Vitality, with the former also offering Toughness. Once you’ve gotten used to the dungeons, boss fights and their nuances, I highly suggest looking into getting a set of Berserker’s Armor just to test your abilities to their limits.
Getting into and used to the elementalist class is a unique experience, relying more on weapon skills than their counterparts, you have 20 weapon skills at any one time; If you’re looking for optimal rotations, I suggest googling anything to do with our resident Dungeoneers, DnT. These guys will have all the information you could ever want on execution.
Here is the guide on DnT’s Staff elementalist. This will be a great tool to you; explaining all the optimal runes and sigils; but don’t this be the be all end all of information for you! You’re no good to your group if you can’t stay alive! So use your own discretion in terms of how much defense you need.
tl;dr: more zerk.
If you prefer full text guides, you can visit DnT’s full text guide on the elementalist here.
