Regarding the Power of Waking and the Disney worlds - you're right on the money! Sora DOES have the Power of Waking, he had it all along like Ven said. I know it wasn't explained well at all - and this may just be my interpretation - but the Disney worlds helped him realize he had it all along. It would have been pretty cheesy and poor writing to have him deliver a monologue of exposition stating exactly how they helped him and I liked that Nomura left it up to our imagination/perception on how he regained it. The way I saw it was that his heart was trying to help him regain the Power of Waking, so it took him to the worlds that would do so - that's why after he heard about "may your heart be your guiding key" only then was he able to open the gateway to Olympus. It then takes him to Twilight Town to reawaken another part of his heart (Roxas), then he goes on to the other worlds and learns lessons from them. Sure, it was the same "Sunday morning cartoon" lessons, but I feel that the way Sora processed them this time around was different - IE through a more mature lens - and were actually helpful to him in the final battle.
You've been killing it in the thread, but this part specifically is something I also agree with and wanted to touch on. The game has made it abundantly clear that Sora at the beginning of the game is nowhere near battle ready for Xehanort. People say that Olympus was a pointless visit, when it was probably THE most important place for Sora to go. At face value, we go because Sora, like Hercules, lost his strength but Hercules gained it back. So we go to ask the man himself how it's done, and he remembers at the end, but Sora decides to figure it out on his own. What does he do next? He's guided through the worlds, as you said! "May your Heart be your Guiding Key" was a thing in KH3 for a reason, and I absolutely agree -- his heart was guiding him in order for him to become stronger and regain the Power of Waking.
Every world had the same core theme, and that was "love". Whether that was the romantic love between two individuals, or it was the bond of two sisters, the connection between a boy and the robot his older brother made, the desire for toys to reunite with their owner, or even the protection of two friendly monsters to protect a little human girl and send her back home safely... It all played a part. What was Hercules saying about regaining his strength, again? He says something to the extent of, "All I know is that she was in trouble. Suddenly, I wanted to save her with all my heart, but... It's not like I could tell you how." And guess what Ven says in the Land of Departure, after Sora says he didn't have the Power of Waking yet? "You never lost it... It sleeps until someone needs it." Up until that very moment, Sora wasn't backed into a corner where it was do or die like Hercules was back in KH2 and had to act.
Sora found out that Mickey and Riku were in trouble in the Realm of Darkness, and what happened? Sora let his heart be the guide, and it led him to Destiny Islands. They get there, they find the Master's Defender, and it guides Sora again. Had it not been for those two situations occurring AND Sora rescuing Mickey, Riku and Aqua, Ven wouldn't have been able to wake up. Sora's heart was strong enough and ready enough by that point. It was the perfect time for him to realize his power again, because imagine just how badly it would've played out had Sora remembered three worlds in that he had the Power of Waking. Terranort alone took out Ven, Axel and almost Kairi with Sora had Donald and Goofy not stepped in.
It's like what has been said in the thread already, I think the pace is fine, because we have to remember that everyone's working on borrowed time. It's either they get the Guardians, or they start picking off the Princesses of Light. And they KNOW the Guardians aren't going to just sit back and let that happen, so that's why things happen relatively quickly. I think if they had expanded on a bit of the characters other than Sora a bit more and let them be playable, as well as even giving Scala a chance to be explored, the pacing complaints would disappear, but I feel like given the situation, they didn't have a whole lot of time to waste.