Young Goodman Brown

Observations:
1. Goodman Brown is more concerned with his wifes safety than his own.
2.) It kind of seems like Goodman Brown doesn't really believe what the older companion is telling him about his grandpa and his father.
Questions:
1.) Why does Goodman Brown continue to travel with him when he really wants to head back to him wife?
2.) Why does the old man have a staff with a serpent on it, what does it represent?