I'm still very new to the game but I have one of each class and from what skills I have on my bird/bear it appeas mages are the only class that can heal. Every class should have some sort of heal. Along with some sort of root/snare. With the way it is now anyone who doesn't want to rely on potions as their only means of healing has to make a mage. I personally think mages are the best because weather its one mob or 10 I can run in and kill them all at once. Maybe make new spells? Some sort of HoT(heal over time) or even better DoTs? For bosses dots and hots would make the game a lot more fun.