This feels like it could use an ability that let you burn wand charges to use it like a weapon. Or, have a base "free" weapon damage/ reach, then you could burn a charge or two to increase damage/range/crit(range or multiplier)/enhancement bonus/special abilities.
like, you can use any wand as a one handed ranged weapon dealing 1d4 damage 20/x2 crit, or a light one handed melee weapon dealing 1d6 damage 20/x2 crit. Then you could burn one charge for 20/x3 or 19-20/x2, or two charges for 20/x4 or 18-20/x2.
simple, but makes a wand a proper weapon.
other things, it would be cool if this had AFCs for different classes. like a warlock learning to add shapes/essences to wands by burning charges, or an artificer learning to charge wands instantly from his crafting reserve.