Getting rid of DCC entirely from mIRC still isn't going to help much. The protocol still exists and it can be scripted in very easily. The same can be said for the fileserver I guess. However, whereas DCC has widespread legitimate usage, I'd have to say the fileserver doesn't. It's literally saying "mIRC can be used for full-on filesharing and here's something to do it", which is a bad statement for an IRC client to make.
As for making it traceable, whether I'm sharing illegal files or not I don't want anyone (and making it open to law enforcement would mean making it open to anyone) being able to obtain details about my computer or of DCC or any other kinds of connections I make. I wouldn't trust anyone to use that information correctly, law enforcement or otherwise. For instance what right would an American organisation have to trace transfer connections I make when the connection in no way passes through any domain in which they have jurisdiction? None. But would they still do it if the opportunity presented itself? Absolutely.
