Great topic, Jim!
I truly think that it doesn't matter how trust-worthy a Realtor(r) is, if the client is distrustful or skeptical by nature. Or, has a dishonest streak.
The importance includes the fact that your agent has to be a transparent conductor of information to the client, and somewhat opaque to the other side, while maintaining their integrity and appearing credible.
I'm looking forward to reading it, Jim!