Strange ... I find Melee combat more difficult in this game than using magic or a ranger !
Magic Blast is very fast and strong spell that used more mana than Magic Missile, so it is
possible to make my manapool empty by using spells.
And there's more than only normal arrows to use

: poison arrows, explosive arrows, stun arrows, ... so have you ever try explosive arrows ?
Have you ever try (playing a mage) Magic Missile or blast + Confusion (passive skill) + Destruction(passive skill) ?
Playing a mage is fun and also possible to become a powerfull mage (my opinion).