I would change how Rachel liked Percy so much. They couldv'e just been friends. That liking of Percy was kinda worthless to me. But a best friend, I would like. (: (Sorry, I don't like Rachel that much. My opinion!!)
To me the story is great! I'd just change a plothole I found. Beckendorf was due to go to NY universiteit in book 5 right? But he was a year-rounder at camp, how could he have even graduated from high-school?
I would change the fact that Luke gave his body to Kronos, but that would change the whole plot of the story XD So I'd change the fact that Ethan joined the Titans...but then boon 5 wouldn't happen XD LOL, then I guess I wouldn't change anything XDXD