Verbal traps for the unwary are crappy rules. A guy shouldn't get DQ'd for what he SAYS when the result of the violation doesn't even affect his score. This should be a DQ for the player that benefits and 1 stroke for the guy who picks up to help him.
I am commenting only on this statement as I just don't know enough about the original rules question.
D--sometimes a player's statement is all you have to go on and one fundamental rule is that if competitors or opponents tee off and make a verbal agreement to not play by the rules, they are DQ'd the instant that agreement is made during the stipulated round or the moment one of them strikes a shot to begin their round after such an agreement is made.
Now, knowledge is key. If they agree to something that they do not know is a violation the Rules treat them differently than if they agree to knowingly waive a rule of golf regardless of whether or not an advantage is ever gained during the round. I actually like the fact that someone wanting to cheat or play by a different set of rules, and thus, play a different game, is disqualified from the same competition as those wanting to play by a uniform standard.
So if you and I say, "you know what, in our match today let's tap down spike marks", the moment our match begins (either of us tee off) we are both DQ'd for an agreement to waive the Rules--violation of 1-3. Even if we play the entire round never tapping down a single mark, if our agreement becomes known we would be rightly DQ'd.
I think I understand what you are saying about not wanting to trap an unwary person (maybe in a 3-3 situation or provisional ball situation). But to let players agree to knowingly waive rules and let them off the hook under any circumstance is a mistake I think.