About the script...

#==============================================================================
#　＋＋　Weapon Enabled Skills　ver. 1.10　＋＋
#　　Script by ParaDog
#　　http://2d6.parasite.jp/
#------------------------------------------------------------------------------
# Skills can now be available if a weapon is equipped.
#------------------------------------------------------------------------------
# ［Instructions］
# Create elements like "sword", "spear", and so on that applies to every type
# of weapon.  Apply the attributes to every suitable weapon.
#
# Tag/Apply the same element to the skill or skills of your choice.
#
# If a weapon is equipped, learned skills are made available.  But if the wea-
# pon is not equipped, the skill(s) with matching elements are made unavailable.
#==============================================================================

module PARA_WSKL
 
  # WEAPON RESTRICTED ELEMENT
  # Skills with this tag are only available if no weapon is equipped.
  # (Ensure that these skills have extremely low PDEF-F scores... '0' is best.)
  NO_WEAPON_NAME = "NoWeapon"

  # SKILL RESTRICTING ELEMENT
  # Only skills with this element tag are available.
  # Any skill without this element is disabled.  Also, skills with this element
  # prevents disabling through the NO_WEAPON_NAME and VARIABLE_WEAPON elements.
  VARIABLE_SKILL = "Skill"
 
  # WEAPON PERMITTING ELEMENT
  # If a weapon and skill both share this element, the skill becomes available.
  # If a skill has two element attributes, a weapon with at least one of these
  # elements will make the skill available.
  VARIABLE_WEAPON = ["Slash", "Pierce", "Strike"]

  # VISIBILITY OPTION
  # (0: Normal / 1: Restricted skills hidden in combat / 2: Restricted skills hidden)
  VISIBLE_TYPE = 0

end

# End of the config section
#------------------------------------------------------------------------------

#==============================================================================
# ** Game_Actor
#------------------------------------------------------------------------------
#  This class handles the actor. It's used within the Game_Actors class
#  ($game_actors) and refers to the Game_Party class ($game_party).
#==============================================================================

class Game_Actor < Game_Battler
  #--------------------------------------------------------------------------
  # * Determine Usable Skills
  #    skill_id : skill ID
  #--------------------------------------------------------------------------
  def skill_can_use?(skill_id)
    if not skill_learn?(skill_id)
      return false
    end
    if not skill_w_can_use?(skill_id)
      return false
    end
    return super
  end
  #--------------------------------------------------------------------------
  # * Determine Usable Weapon Skills
  #    skill_id : skill ID
  #--------------------------------------------------------------------------
  def skill_w_can_use?(skill_id)
    if not skill_learn?(skill_id)
      return false
    end
    # Does attribute of skill and the weapon agree even at one?
    if $data_skills[skill_id].element_set & self.element_set != []
      bool = true
    else
      # Attribute ID of weapon in name
      weapon_elements_name = []
      for element_id in self.element_set
        weapon_elements_name.push($data_system.elements[element_id])
      end
      # Attribute ID of skill in name
      skill_elements_name = []
      for element_id in $data_skills[skill_id].element_set
        skill_elements_name.push($data_system.elements[element_id])
      end
      # The skill attribute which is not restricted by the weapon
      if skill_elements_name.include?(PARA_WSKL::VARIABLE_SKILL) and PARA_WSKL::VARIABLE_SKILL != ""
        bool = true
      end
      # The weapon attribute which does not restrict skill
      if weapon_elements_name.include?(PARA_WSKL::VARIABLE_WEAPON) and PARA_WSKL::VARIABLE_WEAPON != ""
        bool = true
      end
      # Bare hand skill
      if skill_elements_name.include?(PARA_WSKL::NO_WEAPON_NAME) and @weapon_id == 0
        bool = true
      end
    end
    bool = bool == nil ? false : bool
    return bool
  end
end

#==============================================================================
# ** Window_Skill
#------------------------------------------------------------------------------
#  This window displays usable skills on the skill and battle screens.
#==============================================================================

class Window_Skill < Window_Selectable
  #--------------------------------------------------------------------------
  # * Refresh
  #--------------------------------------------------------------------------
  def refresh
    if self.contents != nil
      self.contents.dispose
      self.contents = nil
    end
    @data = []
    for i in 0...@actor.skills.size
      skill = $data_skills[@actor.skills[i]]
      case PARA_WSKL::VISIBLE_TYPE
      when 1
        if skill != nil and !(!@actor.skill_w_can_use?(skill.id) and $game_temp.in_battle)
          @data.push(skill)
        end
      when 2
        if skill != nil and @actor.skill_w_can_use?(skill.id)
          @data.push(skill)
        end
      else
        if skill != nil
          @data.push(skill)
        end
      end
    end
    # If item count is not 0, make a bit map and draw all items
    @item_max = @data.size
    if @item_max > 0
      self.contents = Bitmap.new(width - 32, row_max * 32)
      for i in 0...@item_max
        draw_item(i)
      end
    end
  end
end