Understanding skill descriptions

Hi.
I have been playing for a little while now and I am about to recycle my medals. I thought I had a considerable understanding of the game so far but something is bothering me and I cant understand it myself. I tried reading different posts but that only confused me more…

So I would like to ask about the damage dealing skills and the difference between some main types of them.

1. Lets take something like Goad (Knight Class)
Physical damage +1, +25%, +0.75%/level

So does it add 1 damage to my weapon (if I equipp something dealing psyhical damage) and then adds %?
So for this type (x damage) I need – high STR + good weapon. Right?

2. Now other skill: Stampede (Knight Class)
Piercing damage 35, +70%/level

So does it have base damage 35 no matter what? Meaning that I dont need STR at all and dont need any weapon? (I made experiment and took off my weapon and the damage from stampede was similar…)

3. Psychological Damage: Sonic Blade (Singing Axe)
I have no idea about that type – what makes it stronger? STR? WISDOM? Do I need good weapon to deal bigger damage?

4. Other strange damages: Mana Blast (Sorcerer Class)
Deals:
Darkness damage +10, +12.5%/level
Deals:
Mana damage +10%, +0.7%/level

What influences these?

1) Is correct.
2) No plus means it isn’t affected against outside influenced like strength or weapons.
3) Psychological damage is in it’s own category. In order to increases damage for psych is charisma. However Sonic Blade isn’t completely psych damage. So a better weapon does help.
4) Mana Blast uses dark damage, so items that deal dark/spiritual damage. Mana damage has no way to be increase :(

Now to answer what influences them:
Anything that has “+#, +#%/level” then it can be increased by attributes, weapons, and bonuses. If it’s just “#, +#%/level” then the outside influences have no effect. There is also “#%/level” it does damage based on the targets remaining hp/mp.

Damages are separated into five categories: Physical, Elemental, Spiritual, Psychological, and Mana. Spiritual, Elemental, and Physical are broken down into subcategories.
Spiritual – Light and Darkness damage.
Elemental – Fire, Ice, Lightning, Wind, and Poison.
Physical – Slashing, Blunt, Piercing/

If you have any further questions just reply to the post.