Hello.
Korean Language use two character type that Chinese Character and Korean Character(Hangul)
And I think your first Question¡¯s answer is correct.
There are Three documents represent Korean Language
1. ancient document at 1681
2. Mostly Hangul, a few to some ideographic characters per a paragraph or a page.
3. Hangul Only
if you want more Korean ancient document, please find Jangseogak Royal Archives documents.
i think the ratio is 10:20:70.
i think Korean Text also expands between each Characters.
This Example is W3C Requirements for hangul Text Layout and Typography's example.
And if this Example is correct, Q5 ~ Q7 will resolve itself.
Thanks!
Reference
[1] http://www.w3.org/TR/klreq/
