while early on melee has some issues. im at late game and my fighter is doing just about as much damage as madora. more on crits than her crits. ive got good weapons and armor tho. also on the takeing damage issue. your doing it wrong if you think they can barely take more than a mage. my mages barely have over 1k hp. my melee has over 2k. a death knight can kill my mages in 2 or 3 hits. they can sit there and whack all day on my fighter tank. you just need good gear. and both my melee do more damage than either of my casters. at least in general. if its weak to the element the casters are casting they do abit more. much more elemental resistant enemies later in the game. also cant use tenebrium with a caster. but in general my fighter is way more effective than my mages. course i use one of my mages to buff my melee. and the other is a healer. course i dont like useing the aoe spells since they hurt me too.
If you use essences for crafting (armour coating) you can make your melee practically immune to each element, so that he is even healed by elemental damage. That way you could cast a meteor directly on your melee and he wouldn't give a shit...