Sorry but you're wrong. Donald and Goofy went to Castle Oblivion looking for Mickey - not Sora. Sora explicity says he's looking for Riku. You may want to rewatch the cutsꦆcenes, because this isn't up to interpretation he directly says it.

The meteor shower scene is not made up again you need to rewatch the cutscenes because Naminé states that she can't actually create new memories,♎ she takes existing memories apart and rearranges them. It's a real memory, Nomura simply didn't address it in-game. If you read one of the Ultimanias (I forget which) Nomura states how he at one point wanted to show how Sora received his Crown Necklace and described the event as the same meteor shower that Sora talks about in CoM. In other words, the promise Sora made with Riku on the night of the meteor shower was indeed rea🌸l and happened when they were kids, Riku gave the necklace to Sora and promised to protect him while swinging a toy sword. It also explains why Repliku, who has all of the real Riku's memories, was also able to recall the meteor shower scene. It's because it happened.

KH3's Don't Think twice is indeed a wedding hymn. And the rings shall be the color of the dawn. Dawn throughout the series is associated with Riku. Sunsets are associated with ♔Kairi. Also, Don't Think Twice and the Japanese song Chikai are not translated versions of the same song, no, they are a duet. The lyrics of Chikai answer the statements made in Don't Think Twice. The person in Don't Think Twice is assuring the person in Chikai that it's okay to love each other and to not think twice about it. The person in Chikai is unsure at first, questioning if the person in Don't Think Twice actually loves them. And they use a LOT of masculine verbiage including saying how having such feelings is "d*mn annoying" and things like "I don't believe in Destiny so let's make a vow". The person in Chikai is a male, Riku, not Kairi. Kairi believes in Destiny - Riku believes in Vows.