in reply to Tiny font
Your requirements sound broken to me. You will never be able to reasonably display Chinese at 8 pixels, for example. If it's a display space issue, it would be better to double or triple typeface sizes and provide some kind of display scrolling mechanism.
If I were doing this, I would search for "best unicode font" and experiment with what is available. A good TrueType font will contain hinting which attempts to make display more legible by adjusting weights and corners and such at different sizes. That means a complete rerender for any size change though and it is dependent on the hinting being any good. There are a lot of wonderful open source fonts that were not produced by typographers or were converted from one format to another so they have shortcomings like bad, missing kerning pairs or lousy automatic hinting.