Answer:
A. What we begin to understand about the fellow traveler is that his intentions are evil.
He is the devil and has been helping Goodman Brown's family to do wrong and hide the sins of the Puritans.
Absolutely the entire Puritan community was a sinner and had made a pact with the devil, but they hid behind a non-existent faith towards God, punishing those who they believed sinners and posing as pures when in fact they were not.
What the devil did was to incite them to sin, saying that it was in the nature of human beings.
B. Through this character, Hawthorne tries to demonstrate the hypocrisy behind the Puritan community. And how even Goodman Brown himself, who finally did not agree to surrender to sin, was a hypocrite. He was more afraid that the community would know that he had seen everything and judged him a sinner, than realizing that everything was a farce.
This story shows the punishments that occurred against innocent people by a community that called itself pure and believed it could "do its own justice" as if they were saints, when in reality they were more sinners than the people they were punishing.
