So how is link damage calculated?
It's all based on the stats of the Landsknecht. It's a STR Based attack that deals Elemental Damage and now that I say that, I'm not sure if it's dual-type or not (e.g., Cut/Fire vs just Fire).
...I'll get back to this later when I can test some exacts on it.
Does the +elemental attack up forge enhance the damage of the links?
+ELM Forges work on it, yes. Those work on any ability that deals Elemental Damage (which I believe includes Typeless damage).
I'm thinking of forging it but i'm not sure how useful it would be. I'm actually not sure about a lot of my decisions. I'm always second guessing myself when upgrading equipment, especially when going from slots to slotless gear.
Forging is essentially free (just costs whatever the component is for the item itself, no money) so just follow some basic things for it:
Does the character use a lot of skills that deal Physical (Cut, Stab, Bash) Damage? If so, ATK Forges.
Does the character use a lot of skills that deal Elemental (Fire, Ice, Volt, and I believe Typeless) Damage? If so, ELM Forges.
Does the character just attack normally without using skills? If so, Elemental Forges (the Fire, Ice, and Volt ones, not to be confused with ELM) or Status Effect or Bind Forges.
Losing slots usually isn't a big deal. Each ATK Forge is +3% Damage, for instance, so if you go from 100 ATK to 125 ATK on the Weapon, you'd have needed to lose over _8_ ATK Forges for it to be worse.