I especially like your third suggestion. Even though I'm a relative newbie compared to most Perl Monks, there are questions that even I am qualified to answer. Doing so not only helps the one asking the question, it also gives me a chance to look it up to make sure I'm not misleading the seeker. That means I learn as well.
I don't see a way to enforce this, but I think it's a good idea to answer the most difficult answers you can. If a question is so easy that you don't even have to think about the answer, then let someone else answer it! If high-level Monks constantly answer newbie questions, they are taking away a chance for others to learn.