Custom Game_Event code lags too much!

[MechanicalPen]

I've been bolting on custom features (party members follow the player as events, and enemy line of sight detection) and now my game lags! Anyone good at improving performance, or have any suggestions on how to move the code into the events themselves? I hadn't tried that option because I want the player to still be able to talk to these events so I can't run it as 'Parallel Process"

Here is the update method giving me trouble:

Code:

    #------------------------------------------------------------------------
    # * Update Movement
    #------------------------------------------------------------------------
    def update      
      # Interrupt if not stopping
      no_move = jumping? or moving?
      # Update
      pen_default_caterpillar_game_event_update
      #do enemy stuff
      if  @view_range != nil && !no_move && @view_range > tiles_from_player
        if can_see_player? &&
            $game_self_switches[[$game_map.map_id, self.id, "A"]] != true &&
            $game_self_switches[[$game_map.map_id, self.id, "B"]] != true &&
            $game_self_switches[[$game_map.map_id, self.id, "C"]] != true &&
            $game_self_switches[[$game_map.map_id, self.id, "D"]] != true
          $game_self_switches[[$game_map.map_id, self.id, "A"]] = true
          self.refresh
          return
        end
      end
      # Check if we need to do speical caterpillar handling
      if $game_system.caterpillar.active? && @caterpillar_actor != nil &&
         !no_move && !$game_system.caterpillar.actors.empty? && !@erased
        #debug distances printing
        if $DEBUG and Input.press?(Input::SHIFT) and !$game_player.moving?
          p "My distance from player is: " + (distance).to_s
          p "My prefered distance is : " + (@caterpillar_actor).to_s
        end
        #end debug
        range = @caterpillar_actor
        distance = tiles_from_player
        #if event is pathing
        if $game_self_switches[[$game_map.map_id, self.id, "A"]] == true
          #check to make sure pathing hasn't failed
          if distance >= range+9
            moveto($game_player.x, $game_player.y)
            @move_speed = 4
            self.clear_path_target
            $game_self_switches[[$game_map.map_id, self.id, "A"]] = false
            self.refresh
          end
          return
        end
        #should we do close movement?
        #different moves based on distance.
        if distance >= range+3
          $game_self_switches[[$game_map.map_id, self.id, "A"]] = true
          self.refresh
          return
        elsif distance >= range+1
          move_toward_player
          return
        elsif distance >= range && ($game_player.moving? || $game_player.jumping?)
          move_toward_player
          return
        end
      end
    end

EDIT: So, I feel silly. It turned out my lag issues were caused by a runaway HUD window updating every frame. So instead maybe you guys have tips on how to profile RGSS code or tips on how to prevent lag.