I totally agree with what you say, but what I'm trying to do is build a character who can hold his own throughout the entire playthrough. I like the rogue but as you said before, he is quite weak at start.. He has no control over elements, so I can't sinergize with my fellow mage and more often than not, I'm just hindering the mage's potential because she's afraid of setting me ablaze. This makes me not want to play a melee character. Moreover the typical rogue tasks are of no importance in this game... lock picking, trap springing etc.
So maybe I'd like a class with which I can sinergize with the mage. Yesterday I built some sort of paladin.. sure he fights good and hits hard but... I was impeding my mage all the time. Something in my playstyle is wrong..