My recollection is that there was a very lightweight binary that would launch a single window utilising an existing Emacs process that (of course) you usually alrwady had running, to show a dedicated window for editing a single file - which is Notepad's raison d'etre. So as a Notepad replacement I can't really see a place in the world for something like this.
I am not in any way competent to comment on CJK issues in Emacs as I can't do any of those languages. I can appreciate the desire to address those.
To answer OP's question, I doubt there is much demand for a knobbled Emacs like this, but on the other hand, I think you should do open source software primarily for yourself because doing it for others' sake will grind you down. But if what really pleases you is to make an impact for a lot of other people, directing your energies into solving CJK issues in Emacs itself would be a lot more impactful (though I am sure a lot more challenging too).