For a complete explanation, please look at my answer to this post.
When you only have 1 weapon equipped (no offhand) then the damage will be completely determined by the dps of that weapon.
When you have 1 weapon and 1 shield equipped, the damage will be the same as if you didn't have the shield equiped (so the same as above).
When you have 2 weapons equipped, the damage will be completely determined by the dps of your right-hand weapon. However, since you have 2 weapons equipped it will give you more damage than if you have just 1 weapon equipped, say, as a sort of bonus. I believe the amount of 'bonus' to be equal to floor(dps of righthand weapon / 10)
, however I couldn't do many tests on that statement so it's best to take it with a pinch of salt.
So: always equip your highest dps weapon in your right hand and depending if you want more dps or more survivability you can choose a weapon (any weapon, stats don't matter *) or shield as offhand.
*except if that weapon gives you bonuses such as dual-wield modifiers, %damage, ...!
The wand's damage will not affect skills that do not use weapon DPS. Ex. Magma Spear's "6 Fire Damage over 3 seconds" is not affected by your wands fire damage, but the "XX% of Weapon DPS as Fire" is affected by your wands high damage.
Passive Damage bonuses like "+Y% Fire Damage" apply to all skills that deal fire damage whether they use weapon DPS or not.
Skill damage is also affected by bonuses from stats and armor enchants.
Best Answer
Yes.
If a skill says
deals X amount of Y as Ice/Fire/Poison/Shadow damage
or just plain:deals X amount of Ice/Fire/Poison/Shadow damage
your Focus stat will be used in the calculation of your damage.So if you're going to use a lot of skills that mention Elemental Damage, it makes sense to invest in the Focus stat. Even so, my Outlander uses only skills with elemental damage and only has Focus points invested.
It's also easy to verify this (if you don't mind using the console on a test character).
Just use
Frost Breath
on the dummy, my level 2 hit for about6
damage on average. I then gave him 200 more Focus (= 100% more elemental damage) and he hit for about12
on average.