I have a long history suffering from inputing Chinese in KDE, where scim does not work well, especially when used with Qt applications. Certain applications like KWord will refuse Chinese when using SCIM.

After some search it seems that ‘skim’ which is scim Qt’ifyed version, would support them well. Moreover, this version seems to have better UI than its GTK counterpart. The port (textproc/skim) is now unmaintained, maybe someone will pick it up? I’ll consider picking it up if there is nobody taking care for it.