Quote Originally Posted by Crop View Post
1. When Riku opens Maleficent's heart to the darkness and she turns into a dragon, why after the battle is Riku like "She failed to notice the darkness eating away at her heart" when she kept her heart closed to the darkness all that time, and the only reason the darkness took her heart was because Riku opened it?
As Fynn suggested, she thought she was in control of the darkness in her heart. Riku's keyblade had the ability to unlock people's hearts, and that's exactly what he did. Just turns out that she had more darkness in there than she could really control.

2. So what is Kingdom Hearts, light or dark? First Ansem is like "fill me with the power of darkness" and darkness starts to come out. Then Sora is all "No Kingdom Hearts is light!" and light comes out and destroys Ansem, THEN they're trying to close the door because it's full of heartless, what's the deal?
There are two kinds of Kingdom Hearts: the Kingdom Hearts of worlds, which is a collective of the hearts of each of the worlds and the Kingdom Hearts of men, which is a collective of the hearts of the hearts of people. The former appears in Kingdom Hearts. The latter is what Organization XIII creates in Kingdom Hearts II. There's also a third way to create Kingdom Hearts, but that's got major spoilers for Birth by Sleep. Not sure if you want to go there or not. Regardless, it is a source of great light which inherently attracts great darkness.

3. Why does every gaming series I really enjoy get ruined like this one has been?
That's subjective. I'd argue that while Kingdom Hearts II introduced a number of confusing elements, having played all the spin-offs and side-games, Nomura has done a surprisingly good job of creating a consistent continuity. Birth by Sleep, in particular, is one of the better games in the series, and Chain of Memories was pretty fantastic as well. The other titles (Days, Coded, etc.) each have their place in explaining parts of the story. KH:3D is also looking like it's shaping up to be a strong entry into the series to guide us to KH3.

4. Why is Riku a likeable character in this game but annoying as hell in KH2?
Again subjective. I did not find Riku annoying in KH2.

5. When someone turns into a heartless what determines how powerful the heartless becomes? I used to think it was the strength of the heart, but since Sora became just a Shadow I'm starting to think it's to do with the amount of darkness in a heart. Confirm?
Sora turned into a shadow heartless because shadows are a natural breed of heartless. Most of the other "stronger" heartless are emblem heartless which were created by Ansem in the depths of Hollow Bastion. Because Sora was not consumed by an emblem heartless but rather become one by willingly releasing his own heart, he could not have become much other than a shadow.