I've been thinking about JB's Thief class that automatically succeeds when using skills. I've said before I like this idea, and I've directed some people to his post recently. I've also been thinking about the occasional other solution of saying that a thief's abilities are uncanny, not just ordinary skills, especially in connection with this quote from the original Thief description in Supplement I: "open locks by picking or foiling magical closures". Why not merge the two? Make thieves able to automatically pick normal locks, remove normal small traps, climb normally climbable walls without equipment, or sneak up on, hide from, or pick the pockets of normal (0-level) people; require a roll for truly unnatural situations or if the target's level is equal or higher than the thief's.
Of course, that raises the question: what do you do with the ability to find traps? Does allowing a thief to automatically find a trap ruin the adventure? I'd say "no", not only because finding traps is not actually listed in Greyhawk, but also because the ability is limited to looking in the proper location. In a way, it brings back the old approach to skills: no skill roll, just actual problem solving.
Player: I search the door for traps.
Player: I look it over from top to bottom, examining the frame, hinges and knob in particular.
This would spot things like: unusual substances on the door knob, trip wires or triggers attached to the bottom or top of the door, modifications to the hinges. It doesn't spot needles in the lock, unless the player then examines the lock. Nor does it find a covered pit on the other side of the door, since it won't even be searchable until the door is opened. Traps are still dangerous, even with a superthief.