And in fact, it's worse than you think, because IIRC the archer can't get expert trap before he is fully promoted. In my second game, I had the luck to find a decent item of disarming, and thereafter I had no trouble. If you don't have the same luck, what I suggest is that you find a decently-rated monster which always gives loot, and mephisto its corpse until you get an item of disarming from it.
His ability to disarm traps is one of the reasons I use an archer in MM7. He's not particularly good at it, but at least he can do it. IIRC he's the only character with access to the mirrored path magics who can disarm traps. With my style of play with a Light Path party, I find access to the Paralyze spell is invaluable - and that's a Light Magic spell.
