This is a fun subclass... very cinematic! This makes fighting with just daggers competitive with other weapons... maybe even giving it an "edge". :)

The only tweak I would recommend is the part of "Slash, Slice, and Sling" where if a thrown dagger attack misses, it returns to your hand immediately after. Not for balance, but because I can't see this happening without magic. I would just state this happens only for magic daggers. And maybe whether hit or miss, but only at the end of your turn.

Regardless, sign me up! (thwip, thwip, thock!)