So, I'd like to address how to deal damage as a Conjurer. True, we lack a large variety of damage spells, but the truth is you don't need them. First things first, DoT spells are your friends, due to how efficient they are.

Going off the numbers, Aero does 50 potency in direct damage, plus 25 potency per tic for 18 seconds. Each tic is 3 seconds long, so the DoT effect hits 6 times. This means a total of 200 potency, albeit over 18 seconds.

Stone deals 140 potency in direct damage. There's no DoT, though it does inflict Heavy which is useful for kiting situations.

In addition, Thunder deals 30 potency in direct damage, then 40 per tic for 12 seconds, a grand total of 150 potency.

MP is a little harder to work with, as your level is a factor in the cost, but stone is just slightly cheaper than Aero... but not by much. As you can see, Aero does roughly 4/3 more damage, but only if the buff runs its full duration. So, the idea is to apply Aero (and thunder if you have it) whenever it wears off, and otherwise pelt the monster with Stone. One very important piece of advice though, concerning Cleric's stance (and another reason why DoTs rule): When you inflict a DoT, the recurring damage is based on your stats at the time that you applied it. This means you can use Cleric's Stance, cast Aero, then remove it and go back to healing, and the damage for those full 18 seconds will act as if you had Cleric's Stance up the whole time. This also works with the Raging Strikes ability from Archer, and potions of mind (which convert to intelligence while cleric's stance is up). Simply put, DoT spells do the most damage for the amount of time spent casting them, and once you get into dungeon parties you'll find you often only have a few seconds of free time to throw out a few spells between heals, so make them count! Also, once you get Regen and Medica II, the same rules apply: You can pop Divine Seal or use a Potion of Mind to beef up your healing before throwing those up.