Ok, I'll give you what I have:
Sword Type: Sword, Axe
Spear Type: Pow Hammer (thor's hammer), Spear
Flail Type: Flail, Whip
Boomerang type: Autorang
Bow type: celestial bow
bow and arrow type: concussion gun -
Consumable item type: Throwing stars
Ok, I came up with the concussion gun and the autorang. Autorang has magical properties that enable it to return automatically after contact (hooray for defying the laws of the universe!). Concussion gun shoots concussive blasts of whatever. Frankly, I'm looking for something more flashy and specific than "Pow Hammer" and "Celestial Bow'. No offense, just something like "Thor's Hammer" would be so much more specific, and actually fit in with the story. So, names that relate to mythological personas (real or unreal) would be nice, or even futuristic sounding names...
Second of all, I don't know what a halbert is, but it sure sounds a lot like halberd which is too close to an axe. Maybe you could do it for the axe though, that might be interesting...
Now, with this in mind, still feel free to call whatever you are making whatever you want. Pretty much anything from an RPG looks mythological, so we should be fine there. The transition to in-game should be easy.