Kingdom Hearts World Restoration

So when a world is overcome by the heartless and is destroyed because they 'nom the heart the people who are unlucky also get 'nomed and the lucky ones end up in Traverse Town. Amirite so far?

Because the antogonists of the original Kingdom Hearts game were being so badass and dominating each world one by one without much resistance due to most locals not understanding what was going on and only Mickey working by himself to fight back the heartless a lot of worlds were destroyed by the heartless...

And then Sora came along and took out each of the members of the group that wanted to rule the heartless and Kingdom Hearts itself. Because the emblem heartless didn't get any new orders for a while due to the group being disbanded, Pete being Pete and Maleficent being out of action the the worlds began to come back (either by the passageways between them being unclogged or restoring themselves).

I've understood this whole thing correctly, right?
If so,
How do the survivors who ended up in Traverse Town get back to their homes?
E.g. Mushu or Simba

 

That's mostly right except for the lucky ones ending up in Traverse Town. They have a higher chance of ending up in Traverse Town but they can also land in other worlds like Riku did with Hollow Bastion. You have a higher chance of landing in Traverse Town because it kinda sits inbetween the dark and the light like Twilight Town and Castle Oblivion.

The heartless don't need orders to do something. They rely mostly on instinct so even if somebody isn't controlling them, they still do what their instinct tells them to do. They just couldn't do that though because Sora locked each of the world's keyholes so they could never get to the heart of the world.

The thing is that Mushu and Simba weren't actually in Traverse Town. Their spirit could just be summoned by Sora to whatever place through their summon gem. My theory is that when a world falls into darkness, time doesn't move at all and all things are put on hold. Those who have strong hearts can leave behind a summon gem so their spirits can be called to help the person who summoned them.

 

As was stated by GS the summons were just there as summon stones, just their spirits, their bodies were still consumed by the darkness from when their worlds dissappeared I think. As for the normal guys, I have no idea how they got back to their respective worlds. Maybe they used gummy ships? Well after KH1 it was impossible to freely travel between world so, I dunno... It's probably just a plot hole.

 

If I remember right (sorry, it's been a while since I played the first game) I think that they explained it like this:

There are barriers that keep each world seperate. During the game, those barriers were down (I forget why) and you can use gummi ships to travel to each world. After defeating the final boss and closing the door to darkness, the barriers went up and all of the worlds went back to normal. Even the original denizens of those worlds go back. For example, Cloud has been in Olympus Coliseum the entire time, not Hollow Bastion. But during the ending credits, you see a scene where Cloud returns to Hollow Bastion. I think at some point in the game, even Squall (Leon) tells Sora that they won't ever see each other again, "but they'll never forget each other." That's why Kairi ended up back in Destiny Islands. So what happened with Kairi (and Tidus, Wakka, and Selphie) is what most likely happened to Mushu, Simba, etc. The only part I don't get is why Sora, Donald, and Goofy didn't return to their home worlds. Oh, and Pluto, too (sometimes I forget that he's in the game).