Well, I explained the probable cause of the nicklist issue. As for the two ways of displaying in the channel, I have a feeling that the nick being displayed is treated as an item such as a variable, so mIRC doesn't realize that it should be UTF. When you type in Russian, mIRC knows to use UTF, so it converts the entire line.
These would definitely be 2 features that need worked on for UTF in the next version. I think that, perhaps, Khaled didn't know about networks that support nicks that use these characters, so he didn't make the nicklist UTF or make it so that it converted the lines if the nick is UTF and the line isn't.
