At level 6 I need 23 Int for a magic damage bonus of 3%, at level 8 I need 28 Int for a damage bonus of 4%. So I need 5 points of Int to keep the intellectual damage bonus for 2 levels. The only stat that seems to improve while leveling up seems to be Constitution +17 per point at 6 and +22 at 8.
If you don't find good items, you damage will just stagnate or even get worse? Only regarding you stats and not bonus damage from improving mage skills.
By the way I'm not asking you, just trying to explain what I am concerned about.
The damage of skills actually goes up per level, so the reducing damage from INT balances out.
Mouse over the damage of your abilities, then level up and do it again. You'll notice it always increases.
The only time this doesn't apply with Wits. Wits just gets straight up worse as you level, which I find silly.