Fears
Sasuke is afraid of being weak. If he develops any attachments they'll hold him back from his goal. .He's too wrapped up in one weakness, one person, to realize he is truly very strong. But his strength is also his greatest weakness. If he loses his hatred, he is nothing. What he doesn't see is that you never lose your love.
Naruto is afraid of the darkness. It haunts him, the darkness is made up of the hatred of the villagers, and the loneliness; his loneliness. In the night, by himself, it calls to him, draws him into a vortex he can't escape until the daylight hours where he fills his time with the begrudged company of others.
Sakura is afraid for the others. She knows they are too determined and that they care too much. She loses sleep over them, and is tortured by the thought of them laying still and empty. By the hands of others, or worse by the hands of each other.
A/N: Eh.. I wrote this a while ago… I just typed it up. Like it. Hate it. Molest the blue button and let me know. ;)