Is there a limitation on the number of character traits that each character can have? It seems there is limited room on the data screen, and when I add a trait to a "full" list, a previous trait disappears.

The only limit is how many traits are available in the game total. Yes, they do scroll of the screen which means when you level up you cannot apply points to those which have scrolled but you can still train in them at guilds. Some traits/skills are not really worth developing (sword, staff, dagger and maybe bow are about the only weapons to raise).

Personally, I never found the scrolling off to be a big problem. If you develop your characters carefully you shouldn't have any problems either.

Wyv

The only other one I would recommend training in (and for only one character) is Mace. When you get past Brimloch Roon, the Mace of Mangling can be blessed up to like 70 points of damage/hit, and it stuns (paralyzes) its victims. It's also great for Priests to use. I gave my Valkyrie a Mace of Mangling and she was going to town on the Demons. I think it has a percentage chance of Critical Kill as well, or that may have been her "Deathstrike" training...

-Sazerac