I dislike that having 0 skill in (example) two-handed weapons and 2 points in Tenebrium handling should makes someone a better two-handed tenebrium swordsman than someone with a maxed two-handed weapon skill and 1 point in Tenebrium handling.

Respec is so poorly implemented I don't see it as an option. People should not have to risk permanently losing skills/spells just to respec for Tenebrium handling.

As ability points in Tenebrium represent your ability to handle the material safely, I had suggested that the Tenebrium requirement on the weapon subtract from the normal weapon skill (representing the difficulty in handling a Tenebrium weapon safely), and each point in the Tenbrium skill offsets that penalty.

i.e. a tenebrium requirement of 3 on a two-handed sword applies a -3 to the user's two-handed weapon skill, but can be lowered to a penalty of -1 to the two-handed weapon skill if the user had a tenebrium skill of 2.