I wouldn't call crafters unfair, but they're definitely very powerful and very easy to make. Making them stronger probably isn't a good idea.
If I were to rebalance the elements I would probably ditch the fire, water, earth, air, spirit combo and come up with something else. Something with elements that can't be so easily rationalized into doing everything. I would want one element for physical attacks and offensive maneuvers, one for physical defences and defensive maneuvers, one for veils and other mental stuff, and one for movement and controlling the landscape. I'd like to add a fifth element, but I can't think of a good domain for it.
This would naturally make wizards a bit weaker and focused practitioners a lot weaker, but it would solve the problem of elemental interchangability. And it would let us dispose of that bloody offensive/defensive evocation focus rule.
What do you guys think?