Not Intelligence.

It's basically the good ol' sand trick.

more like Wit. Since it's basically you playing dirty.

This is why I think all weapons and abilities should scale with either multiple attributes, or not tie them to any. That way you'd have more build diversity.

(and yes, it'd be fun playing a dirty-fighting scoundrel who throws dust and uses choloroform + some other magic damage stuff while still being a finesse character)

All the combined skillbooks should scale off of the highest relevant attribute, or simply be level-based only. The way I see there's no reason for warriors, rangers, or scoundrels to even dabble in them otherwise.