Try KDE Control Center, Appearance and Themes, Fonts. I find that simply choosing different fonts here can drastically improve things (in KDE at least). I have no experience with Chinese fonts, but I have been able to get some Greek and Hebrew fonts to look pretty good....all I did was install them with the KDE control center by going to System Administration, Font Installer. Trying out some different fonts in the Mozilla preferences and in Konquorer preferences has also drastically improved things. Good luck.