Does a weapon have any damage affect on his "A" slot skills? If not, what's the point? I'm confused....
The weapons stats will have an impact on the characters damage. Int, +poison, +fire, etc
Spells do damage based on a % of the damage your weapon does.
For example: My Vampiric Steel Wand of flame does 15-24 damage, and my magic missile attack does 150% of weapon damage. So every time I attack with that, I will deal between 22.5 and 36 damage to the target.
If you go into your options menu, you'll find a 'Show Advanced Tooltips' option. If you check that box and then go back to your skills, you'll see that they now all reference Weapon Damage.