Since you're here, I wish to ask which of the two 'balance' goals you are working toward:

1. All of the Magical Weapons are equal in strength.
2. All Magical Weapons except Vanilla are meant to be more powerful than Vanilla, using it as more of a 'base' Magical Weapon that has more magical properties added to it, creating things like Piercing and Poisoned, et cetera.
 

I think that every Magical Weapon should have the same Modifier spread, say, from -2 to +5 (I'd like that, myself).