Well if you want to go with no magic then you'll need stealth and play commando
You need 1 point in water magic for healing - unless you want to rely on waiting for cure wounds to finish its cooldown or spend money/make limited potions.
I did manage to win against one of the bosses (in the lighthouse) using stealth with 2 lone wolf rogues. It took a while though and it was mostly 'cheating' the AI. But even then invisibility (lvl 7 air skill) has a short cooldown and won't be accessable without air magic.
The low level spells are very effective, Midnight Oil/Flare or Fireball combo works wonders, minor heal beats all other healing spells IMO as even though it heals less it heals more in the long run. Rain is imperative for certain quests, become air is also useful as well as fortify.
Last edited by Jackal2200; 12/07/14 05:20 PM.