How is Young Goodman Brown changed by his experience in the forest? Does the narrator endorse Brown's unwillingness to trust anyone?
As the question implies, Goodman Brown is changed to the point tht he trusts no one and is haunted by his experiences. He questions the reality of what he has seen, but cannot get the images and revelations out of his mind.
It seems apparent that the narrator does not endorse Goodman Brown's attitiude that he adopted after his encounter in forest. The ending line tells us that Goodman Brown's dying hour is misery. Thus, he never overcame the literal and figurative demons of that night.