Roxas' days in Organization XIII unimportant. Don't see what's so important about learning someone's life in a group when in KH2, you get ALL the important details. The tormented ones are important because of coded. Before coded, all that was important was fight Xehanort's Heartless, his Nobody and, possibly, his complete being. Riku's time when Sora was asleep was covered in KH2; he was snooping around about Organization XIII alongside Mickey and protecting DiZ, Namine, Sora, Donald and Goofy. The data inside Sora wasn't part, again, of the standalone trilogy plot. See, problem is, if the series were, once again, a standalone trilogy, KH3 could have covered KH1 and 2 quite nicely.