1. So, you could for example relly on several different summons (Ice, Fire, Iron) as to not need to wait for the long Cooldown and to also adjust to the proper elemental resistances, but that build should also have Staff Mastery and Mage Armor (at least).
2. I made one interesting "alternative Elementalist", on which instead of Fireball and Blizzard, I use Combustion and Disintegrate. So, it has Zap 3, Combustion 3, Disintegrate 3, Staff 4, Mage Armor 3 (and Sparkling 1 exclusively for the Ark).
3. This weird combination plays just like an Elementalist, but better (imo)