But did they remembered how they died or their name, their past?
They didn't die. And yes.
I think org members 2-13 didnt remember anything(except xemnas,he obviously know everything that's happening) cause if they remembered who they were.Why wasting their time being back as their original selves if they can go back to their own world and live a life there?
You missed the entire points of being a Nobody.
They're missing their Hearts.
They can't truly love, they can't truly hate, they can't truly
feel, save for one simple thing, being that their Hearts are
missing.
Nothing good and a lot of bad.
The Org didn't really want their original Hearts back. That's all but evident by the "New You" concept in which they even received the X into their names - to
differentiate themselves from who they used to be.
That didn't stop them from wanting a Heart though.
Oh, and 1-12 seem to remember their past just fine. Xigbar did enough to remember having met
Terra, Aqua and Ven, and that happened
before he became a Nobody, when he was still an apprentice of Ansem the Wise's.
Memories stay with the
Heart. When the Heart becomes a Heartless, however, the Darkness severes the ties between the Heart and the Memories, leaving them with the Nobody that remained.
Proof of this would be Sora that once the Darkness was removed from him via Kairi's PoH powers,
regained his Memories, leaving Roxas with none.
And xemnas's intentions to KH was only to have a heart and emotions again so he can wield a keyblade and use KH to rule the worlds.
I really have to wonder where you're getting any of this from. Xemnas
mocked the emotions that came with the Heart, and saw that as the main weakness for Sora which is why he could manipulate him so easily, up to the bitter end.
He wanted a Heart so he'd be whole and thus more powerful, alternatively, just to use KH. The Keyblade had nothing to do with this as far as we know, and certainly not
emotions.