Some skills list "Weapon Damage: X%" as one of their stats, for instance in the second circled area in this screenshot:
What does it mean? Does it mean every attack with the skill deals an additional percentage of the weapon I'm currently wielding?
If so, do other traits of the weapon, besides damage, also apply? For instance, will a weapon which reduces the target's armor on every hit also make the skill reduce it? Will a weapon generating mana on every hit also do that when using the skill?
What happens when I'm dual-wielding weapons? Should I strive to wield just one powerful weapon instead of two weaker one to maximize spell damage?
And does the weapon attack speed make any difference? Should I aim for higher-damage over higher-DPS weapons if I want to maximize skill damage?
Finally, the first circled part apparently shows the effect of the magic ability on this skill. But I thought the magic ability also affects every weapon's magic damage. Does this mean the magic ability modifier is actually applied twice to this skill, once directly and once indirectly via weapon damage?