Arctic Spear is under performing when compared other projectile skills. It has little AoE support but more importantly, it does not benefit from Spell Casting Speed Score. So I suggest a new modifier or behavior to make it more worthwhile:

Enable it to be cast while you are charging another skill. This may either be Arctic Spear's default behavior or some modifier (probably 2-3 points of worth) can give you this benefit.

Thank you for reading my suggestion.