A character develops a separate weapon skill for each category.
The skill is a GENERAL Skill and therefore has a base role or 11-.
The skill allows a player to use weapons of the class at full effectiveness.
A skilled character can use weapons the character owns or has reasonable access to at full effectiveness without any skill rolls. However, weapons obtained very recently to or during a battle require a character to make a successful skill roll to use. If the character fails the skill roll the character suffers non-proficiency penalties until they have a chance to practice with the weapon.
Familiarity allows a character to use a weapon at full effectiveness only in practice situations. In combat the player will suffer non-proficiency penalties.
Why Level Up The Skill
Generally speaking there is no reason to level up a weapon skill. However, some advanced maneuvers can be developed which require a skill roll with the weapon skill of the weapon being used. In these cases the user may need to develop further skill with a weapon to increase the likelihood of success at an advanced maneuver.