One possible option that could be added for Dex characters to level the playing field with other builds, yet still keep playstyles diverse: dagger-based consumables.
Same idea as the specialty arrows used by bow users (ie. ranged Dex characters), but for dagger users (ie. melee Dex characters). In reality, these could be all manner of tricks and traps.

Couple of caveats needed for them to function properly:

- They need to be based on using them for a weapon attack and have no cooldown (otherwise, may as well add more Scoundrel skills).
- The damage effects from them should scale with either weapon damage or Dex level, depending on the effect.
- They need to produce effects that are unique and powerful enough to be worth using, but be limited by supply/cost and scope of effect to make them situational.

Couple of ideas/examples:

Scorpion Wire - causes a marked target to be dragged back to you after moving X meters away.
Balm of Agony - extends the duration of damage over time effects on the target by X turns.
Searing Tincture - removes damage over time effects on the target, dealing damage based on their remaining durations.
Numbing Salve - causes the target's next attack to make them take damage and lose 2 AP.
Tongue-Tying Toxin - causes the target's next spell to make them take damage and lose 2 AP.
Time Bomb - causes an explosion at the target's location at the end of their next turn.