The fix I adopted for Knock was one I read about on the forum somewhere a while back.
I'll try to look up the exact wording, but basically it let the caster make a "Strength" check to burst the lock, except replacing his Strength modifier with Intellect. Hence, a totally different mechanic from either picking the lock or the original spell.
Your version of Find Traps looks alright. I might not bother to include the max cap though. How often is this going to come up in epic play? And how often will a character be able to locate epic-level traps unless they are heavily specialized in it?