I've been wondering if Nomura is thinking it. For example, why is it that as soon as Sora has his Awakening, DI falls and not too long from that we see Ansem SoD at the door? Why is it that Sora stole the KK from Riku if Sora has Ven's heart which is already capable of weilding a Keyblade? Where has Mickey been prior to KH1? If the worlds started falling to the darkness, why wait 9 years?
Sorry if it's a waste of a thread, I was generally curious.
Okay Sora's awakening had nothing to do with DI being taken by darkness, there's no connection there. XH appeared in DI most likely because he sensed a POH there (kairi) and he sensed the darkness in Riku's heart and knew Riku could be an excellent host if he submitted to the darkness Also I believe Nomura said XH may have went to DI in KH1 partly due to him having memories of MX's time there.
Sora didn't steal the KK from Riku, the KK went to Sora after Riku dissapeared into the darkness. Okay, Sora couldn't wield Ven's keyblade because Ven's heart was sleeping in Sora's heart and was thus unactive, meaning Ven's heart couldn't call upon his keyblade. But after Riku dissapeared into the darkness, right at the moment the KK was going to choose Riku, but because he was absent, the KK went to Sora because it sensed the heart of a keyblade wielder in him, Ven.
Mickey was traveling to Traverse Town sometimes because it was during his travels that he met Leon and learned that Leon was helping people escape to Traverse Town after they lost their worlds to darkness.
Now the reason that Mickey waited 9 years to do anything about the heartless, was because he COULDN'T do anything. Even if Mickey had gone to the dark realm and found the dark realm's keyblade, he still couldn't have closed the Door to Darkness, because there was no keyblade wielder to close it on the side of the realm of light.
Basicaly Mickey had to wait until another keyblade wielder was chosen, so their would be two keys, and they could close it from both sides. When Sora was chosen to wield the keyblade it became possible to close the DTD. So it was only at the start of KH1 that Mickey entered the dark realm to find the keyblade cause he knew very soon Sora or Riku would be chosen to wield the keyblade.
EDIT: Also the Keyblade doesn't give a flying flip if someone's heart is more alligned with darkness or light. It chooses the strongest heart and by the time that Sora reached Hollow Bastion, Riku's heart was stronger and thus he could take back the KK.
But once Sora realized he only needed his friend's to be strong, the KK realized Sora's heart was stronger and so returned to him and chose him as it's permanent master.