chest (black or otherwise) in the whole game that couldn't be opened safely with Master Disarm (7 Skill points)+ the 4 point bonus you get if you hire (then fire) the RPC assassin in the Drangheim Tavern.When I play my favorite party (GAAP), I always make my Gladiator the Disarmer of Traps (even though both Assassins can GM the skill). That way I can split Perception and ID Item between them (they can Master both) and save on skill points.
You would be amazed at how much damage an assassin can do when armed with two artifact daggers with 25 or so points in GM Blade.