How should a monk address subjective questions?
Being attached to some rule about how to answer certain questions isn't the point.
Good answers come out of being present and aware.

The same question will be answered differently at different moments depending on what the moment calls for.

"Every possible opportunity" is an interesting phrase. If someone isn't ready to learn something there no opportunity to teach him something. Being a good teacher means to know what someone can learn and then give him that lesson. It's not about throwing a lot of spaghetti on the wall and hoping that something sticks.

Christian missionaries do thing that it's the intention that counts. Christian missionaries will lecture someone whether or not there an opportunity to teach something. For them the act in itself is important.

Buddhism is different. It's about being skillful and only teach when the student can learn. Teaching requires patience and waiting for a possible opportunity.