Note that the NWN hardcore is only for traps, not locks. Anyone can get a high open lock and eventually be able to unlock anything. Rogues tend to be the easiest to do so with due to it being a class skill for them, but it's not exclusive even as a class skill to rogues. You'll encounter DC's as high as 60 or more for locks in dungeons.
Any Search DC 35+ Trap cannot be spotted by a non-rogue, and any Disable Trap DC 35+ trap cannot be removed by a non-rogue. Non-rogues CAN however 'Recover' traps over DC 35, if they can spot it(Either it has a search DC of 34 or under, or a rogue flags it for you) You might encounter traps that can be seen by anyone, but have a DC of over 60+ to recover.
Any Search DC 35+ Trap cannot be spotted by a non-rogue, and any Disable Trap DC 35+ trap cannot be removed by a non-rogue. Non-rogues CAN however 'Recover' traps over DC 35, if they can spot it(Either it has a search DC of 34 or under, or a rogue flags it for you) You might encounter traps that can be seen by anyone, but have a DC of over 60+ to recover.