There is a huge difference between shadowblade which locks you into a small set of weapons. Shadow Hand associated weapons include the dagger, short sword, sai, siangham, unarmed strike, and spiked chain.
BUT I took the Fighter Targetteer (which was approved list (Dragon magazine)) to get dex to damage with ranged weapons as a gunslinger.
Vital Aim: The targetteer may add his Dexterity modifier to his damage rolls with a ranged-weapon attack instead of his Strength bonus. The targetteer cannot replace a Strength penalty to damage rolls with his Dexterity modifier unless his Dexterity modifier is also a penalty. The targetteer cannot use his Dexterity modifier to replace his Strength modifier when attacking creatures immune to critical hits.
Since we are discussing approvals for PF content and how it's inherently disallowed. Here are 3 PF source legal dex to damage feats that offer other weapon choices.
Slashing Grace (Combat)Pathfinder Roleplaying Game: Advanced Class Guide © 2014, Paizo Inc
You can stab your enemies with your sword or another slashing weapon.
Prerequisite(s): Dex 13, Weapon Finesse, Weapon Focus with chosen weapon.
Benefit: Choose one kind of light or one-handed slashing weapon (such as the longsword). When wielding your chosen weapon one-handed, you can treat it as a one-handed piercing melee weapon for all feats and class abilities that require such a weapon (such as a swashbuckler’s or a duelist’s precise strike) and you can add your Dexterity modifier instead of your Strength modifier to that weapon’s damage. The weapon must be one appropriate for your size.
You do not gain this benefit while fighting with two weapons or using flurry of blows, or any time another hand is otherwise occupied., Fencing Grace (Combat)Pathfinder Roleplaying Game Ultimate Intrigue © 2016, Paizo Inc
Your dashing style and fluid rapier forms allow you to use agility rather than brute force to fell your foes.
Prerequisite(s): Dex 13, Weapon Finesse, Weapon Focus (rapier).
Benefit(s): When wielding a rapier one-handed, you can add your Dexterity modifier instead of your Strength modifier to that weapon’s damage. The rapier must be one appropriate for your size. You do not gain this benefit while fighting with two weapons or using flurry of blows, or anytime another hand is otherwise occupied.
In addition, if you have the panache class feature, you gain a +2 bonus to your CMD against attempts to disarm you of your rapier while you have at least 1 panache point. and Dervish Dance (Combat)Pathfinder Campaign Setting: The Inner Sea World Guide. © 2011
You have learned to turn your speed into power, even with a heavier blade.
Prerequisites: Dexterity 13, Weapon Finesse, Perform (dance) 2 ranks, proficient with scimitar.
Benefit: When wielding a scimitar with one hand, you can use your Dexterity modifier instead of your Strength modifier on melee attack and damage rolls. You treat the scimitar as a one-handed piercing weapon for all feats and class abilities that require such a weapon (such as a duelist’s precise strike ability). The scimitar must be for a creature of your size. You cannot use this feat if you are carrying a weapon or shield in your off hand.