Here are some of the more interesting Variables and Restrictions for the Weapons Attribute that you may not have encountered before:
Blight -- double damage if target fails Body Stat check, or only 1/5 damage if successful. Great for representing poisons.
Helper -- Allows others to use your weapon, like several weapons on a mecha Item. Used to be "alternate weapon," but now it's rolled into the Attribute.
Insidious -- Attack bypasses Armour. Extremely powerful!
Reach -- Character attacks first in melee, regardless of initiative (think lance vs. sword).
Targeted -- Weapon only damages a specific type of foe (like a holy avenger sword).
Hands -- Weapon requires two hands to operate. Think big-ass guns!
Ingest -- Weapon must be ingested to be effective. Mainly for poisons.
Imbue -- OK, this is actually not a Restriction for Weapons but for other Attributes. Still really neat though. The character does not use the linked Attribute directly, but instead grants its use to others for the duration of a scene or event. This is great for blessings, wish-granting, technical upgrades, etc. For example, a shaman might have Healing (Imbue), which allows a chosen character to heal others while away from the tribe on a sacred mission. A great addition to BESM.