I can highly recommend re:coded purely for it's gameplay alone. It is the best implementation of the command deck the series has to offer. Its story while not meaningful in the big picture does have a few scenes that elaborate what was going on in KH1. Its definitely worth playing.

I don't believe it is used. I thought it might have been used in a summon cutscene but it doesn't appear to be in one either, and i can't think of a world it would fit in except for Halloween town maybe but im fairly certain its not used there either

Since you pointed out something that cannot be unseen once you have seen it i shall do the same. If the language kh1 is being played in is japanese the pop up for "Tech" becomes "Tech!!". When the game was translated they never adjusted the spacing of the pop up so there's a noticeable gap.

Yeah probably, it would be a massive pain but you probably could do it if you were up for it because otherwise this is one of two mandatory magic casts in the entire series i think (days tutorial has you cast fire without a keyblade so you are forced to use fire once)

Here's something fun i learned recently about the door to Merlin's house: in the revisit to traverse town red nocturnes spawn in the third district and you can block their fire to open the door. It only works if its Sora redirects the attack, the red nocturne by itself cannot open it

During any fight with sabor in the bamboo thicket she can be made to fall through the floor with good positioning near the rock in the middle of the room. She can hurt sora from below and will eventually return from being underneath the floor after she jumps again

With kingdom hearts 1 and especially stuff about the PS2 version of final mix is that it can be incredibly hard to find info on something that only happens on a specific version. PS2 final mix has a few things unique to it that lack substantial documentation, if it even is, so i gotta do it myself.

Glad to help, i happen to be a massive kingdom hearts fan so this obscure knowledge is what i love. I'll make sure to cover anything else that's missed and occasional version differences that happen to be relevant because in true kingdom hearts 1 fashion theres about 5 major revisions of this game.

So fun fact: if you somehow got to the tea party garden before doing Alice's trial there will be a tree blocking the door to the upside down bizarre room. Supposedly you can see this without cheats but i have yet to see a way to do it with video proof

You brought up that Alice has the same va as the movie, i can actually elaborate on this. Its common for disney to ask the original actors if they want to reprise their roles (also known as first right of refusal) for any sequels and video games. The ones that they couldn't get use impressionists.

My favorite version of this is glitch is when all the text was just obtained e repeated throughout the cutscene.
Credit to stickman sham for the video
youtu.be/eEfCYcBrmdA