Answer:
#1 an allegory is
a story, poem, or picture that can be interpreted to reveal a hidden meaning, typically a moral or political one.
Explanation:
I already answered #2 seperately.
#3 He at first thinks his sheep think of nothing but eating and sleeping and though he loves them he has a mild disrespect for them for only living for food and water. That of course changes when he realizes later that they a part of all things, connected, as he is.
The sheep symbolize the sort of existence lived by those who are completely blind to their Personal Legends. the sheep, in their quiet yet fulfilled lives, symbolize the values of humility and simplicity.
#4 The archetype of a shepherd describes the life of a caretaker, a leader, someone who looks out for those around him and watches closely over his flock. This affects the meaning of The Alchemist because Santiago becomes a beacon for all those around him while pursuing his personal legend. Sometimes this archetype symbolizes a savior.