On the fairness issue:
A matter related pretty directly both to this subject and to this module is the thief class. In the OD&D Supplement I: Greyhawk presentation, the thief had no special ability to find traps and the special disarming chance was limited to ability to "remove small trap devices (such as poisoned needles)". In the 1e PHB, it "pertains to relatively small mechanical devices such as poisoned needles, spring blades, and the like".
Many players seem to have considered it necessary to give the class "niche protection" both by expanding its relevance to traps and by prohibiting non-thieves from dealing with them effectively (or doing things similar to, but qualitatively different from, other thief functions). Gygax did not see it that way, and the designers of 3.5 included a note on p. 73 of the PHB that "It's possible to ruin many traps without making a Disable Device check."
Ability scores likewise have stipulated game effects, and going beyond those may be problematic in terms of how the game was designed to be played. The 3.5 PHB, at page 10, offers some suggestions for using ability scores to inform role-playing.
It might be "fair", in a sense, to prohibit well-reasoned actions or require foolish actions if -- and this is a big IF -- the handicaps of clumsiness and poor stamina and so on are imposed as powerfully. But is that even possible? Learning, reasoning, common sense, intuition ... these are the qualities the player actually brings to the table. Making choices is the only way he or she can actually play the game. Crippling the input of a player's decision-making faculty is, IMO, a much more fundamental and far-reaching thing than merely reflecting an imaginary character's muscular strength or personal magnetism.
A wizard with an intelligence score of 20 certainly has insights beyond the ken of any player. If such uncanny thought processes need ever be tested, then a dice-roll would be the way. Any problem a player even of genius-level intelligence in the real world could grasp would bear no resemblance. Such situations, though, are probably of limited applicability in the game. In fact, I would say that skill ratings should pretty much cover them. Brilliance doesn't make its full difference except in someone's field of expertise, and ignorance often enough trumps intelligence.
A fighter with an intelligence score of 8 or 9 is just slightly below average. If the 3d6 spread is normal, then 37.5% of normal people have intelligence scores of 9 or less, almost 26% 8 or less. Maybe D&D players skew higher than average, but probably not as much as D&D player-characters.
The average player-character is above average to start, and with attainments of levels transcends normal human limits altogether. Perhaps it may help -- if one is tempted to go to extremes in by-the-numbers role-playing -- to think of the player's influence as representing in part luck, divine favor, or some other factor associated with a character of such extraordinary caliber and undertakings. The player's knowledge and perspective give the character another edge over most people in the imagined world.
The this-worldly bottom line is that D&D was conceived as a game to entertain and challenge the very real players. Having a character die horribly in the Tomb can be entertaining -- but the chance to do one's best to survive is key to the challenge.
