Pathfinder draws a strict distinction between unarmed attacks and weapons. Does this distinction invalidate the benefits of the "Finesse" trait, when applied to unarmed attacks?
Almost all characters start out trained in unarmed attacks. You can Strike with your fist or another body part, calculating your attack and damage rolls in the same way you would with a weapon. Unarmed attacks can belong to a weapon group (page 280), and they might have weapon traits (page 282). However, unarmed attacks aren’t weapons, and effects and abilities that work with weapons never work with unarmed attacks unless they specifically say so. p.278
This rule says that weapon traits can apply to unarmed attacks, but that only things which explicitly say they work with unarmed attacks can apply. Now, look at the text of the Finesse trait:
Finesse: You can use your Dexterity modifier instead of your Strength modifier on attack rolls using this melee weapon. You still use your Strength modifier when calculating damage. p.282
So on one hand, we can apply the Finesse trait to unarmed attacks, but when we apply it, we find that its mechanical benefits apply only to melee weapons, and not to unarmed attacks.
So from my reading, this means that any additional rules which apply to the Finesse trait, would also apply to unarmed attacks. However, unarmed attacks would not be able to substitute Dexterity for Strength on attack rolls, because the Finesse trait explicitly says that only "melee weapons" gain this benefit, and not "unarmed attacks". Is this a correct reading, according to the rules as written?