[Armin]

Okay, I managed to squeeze this in before I leave for the day. Here's what I've got, as an Attribute:

[Stats]
Encumbrance Effects, basevalue(1), display(No), 
	gives(_
		=-char::enclevel to SK:Climbing,
		=-char::enclevel to SK:Judo,
		=-char::enclevel to SK:Karate,
		=-char::enclevel to SK:Stealth,
		=-char::enclevel to EQ:Rapier::skillscore,
		=-char::enclevel to EQ:Rapier::parryscore,
		=-char::enclevel to EQ:Saber::skillscore,
		=-char::enclevel to EQ:Saber::parryscore,
		=-char::enclevel to EQ:Smallsword::skillscore,
		=-char::enclevel to EQ:Smallsword::parryscore_
	),
	conditional(_
		=-char::enclevel to "SK:Main-Gauche" when "striking or parrying",
		=-char::enclevel to SK:Rapier when "striking or parrying",
		=-char::enclevel to SK:Saber when "striking or parrying",
		=-char::enclevel to SK:Smallsword when "striking or parrying",
		=-char::enclevel to EQ:Large Knife::skillscore when "used as Main-Gauche in combat",
		=-char::enclevel to EQ:Large Knife::parryscore when "used as Main-Gauche in combat",
		=-char::enclevel to EQ:Small Knife::skillscore when "used as Main-Gauche in combat",
		=-char::enclevel to EQ:Small Knife::parryscore when "used as Main-Gauche in combat"_
	)

The gives() gives outright, direct penalties to the Climbing, Judo, Karate, and Stealth.

It also gives direct penalties to the levels listed for skill and parry in the attack tables for Rapier, Saber, and Smallsword. Unfortunately, Main-Gauche isn't actually a weapon we can target, since it usually uses a knife.

The conditional() block adds a conditional penalty, which basically just notes that the penalty should apply in certain circumstances. We use this to note the penalties that will apply on the Main-Gaucher, Rapier, Saber, and Smallsword skills. We also use this to note the penalty for the Large Knife and Small Knife equipment items, but that often won't be shown in any useful fashion.

So, Main-Gauche is a problem, because it's a special skill that uses a Knife, so there's not really a way that I can see to target it universally for a penalty or not; you can't really tell from a 'meta' point of view if it's a Main-Gauche or not. It will probably require creating a modifier that can be applied when it's primary use is as Main-Gauche.

Remember, if you use this, add it to your custom data file, and any existing characters that use it will need to Resync Attributes to get it applied.