I don't mind about the voice, tbh I'll be more than happy just to finally get to play COM (PAL region, got no remake).
Even if they didn't include the days cutscenes or FM content, I would still get it just to play COM, it's the only one i'm missing in terms of story (have BBS, KH1, Days, Kh2, coded, 3D)
I know what happened in it from reading summaries ages ago when I first got into the series, but I want to play through it myself ):

In the English version, all text will be English. All voice acting will be in English.

There's nothing there to suggest the English version will have Japanese voice acting or Japanese text.

1) See, I'd prefer having Sora's old voice. Those final mix cutscenes already have his english voice (not sure why...), so I'd just personally like the nostalgia of Sora's squeaky, high-pitched kh1 voice that we only have for that first game, and that we'll never hear again in the future.

2) Hm, that's interesting, but you could easily argue that Sora just happened to still remember Pooh for some reason at this point, probably because it was such a small and unimportant memory that it was probably initially looked over in the memory-erasing process (I mean, they seem to forget Hollow Bastion pretty soon despite all of the significant things that happened then, so I think some of the more important memories might have went first). And of course, if Sora still remembered Pooh, Pooh would react and remember Sora the way Leon and co. did as well as Tidus, Wakka, and Selphie did in Destiny Islands.

3) YES.