What symbols do you see being repeated? How do they tie to theme? Character? Plot? Conflict? Why might the author have chosen these symbols?

There is the blue Kite as you mentioned before. The monster in the lake symbolizes the triumph that both boys have together and their inability to triumph alone. The pomegranate tree is a place of communion for both boys. These places tie Hassan and Amir together in a way that transcends friendship. Their experiences foreshadow the news that they are indeed brothers.