Shredder Claws, Orion Khopesh, Hades' Pitchfork, Explosive Kunai, Excalibur Knives, Bone Dragon Knife, Deadpool's Sai. To me, they just feel very floaty.
Also, the Fossil Shuriken and Eclipse Glaive really don't feel right with no rotating animation.
Perhaps slightly less stats and/or speeds for most of the items.
Some of the armor's speed bonuses are quiet fast, perhaps a little too fast. The armor lights seem quite bright and large.
This is mainly judging from Vanilla balance though.
This mod is a very good concept, especially by allowing the throwing class to be useful into and beyond Hardmode. That's what got me hooked.