Answer:
Purpose - Ralph Waldo Emerson's whole purpose behind writing "Self-Reliance" was to try to get people to start avoiding conformity. He believe in order to be your true self you have to start listening to your conscience and be yourself.
Audience - He was mostly targeting young people specifically men, who were educated and taking on new opportunities.
Theme - Start making your own choices witch you believe to be correct, listen to your guts. Avoid all types of conformity your instincts are key to a happy life.
Rhetorical strategy - Emerson wanted the world and everyone in it to be unique and diverse. He used pathos, repetition, motivating diction, and metaphors in order to try to portray the beauty in being yourself.