A dagger is not as good a weapon as an axe in melee. Not to say that it can't be used effectively, but range is really awfully important. Daggers have other virtues: they can be concealed, thrown, and used in grapple. Perhaps those should be icons on the weapons chart...and perhaps the dagger should be a grapple-centric weapon. Barring hilt-bunch, no other weapons are grapple effective. They can perhaps cause 1 dmg, but their destructive capacity is limited.
Unarmed could certainly be a 'weapon style' in much the same way 'Mounted' is.
Focusing on the use of daggers & knives...
Shoves, trips, grabs, throws.
Also useful for claws and bite attacks. And elbows and knees.
Draw from Oriental Adventures...Gentle Way, Mighty Works, Foot&Fist, Empty Hand, Pressure-Points...
Or pull from Avatar...
Waterbenders (T'ai chi ch'uan),
Earthbenders (Hung Ga kung fu, for the most part)
Firebenders (Northern Shaolin kung fu)
Airbenders (Baguazhang)
..which explains why there aren't any. It went away with the martial arts. Which is sad.