Yep, I know how /root works. But the term "root directory" refers to /.
Anyways, since you should have another ordinary user somewhere around /home, why don't you try copying the necessary files and folders from there? Which ever that would be... Maybe at least .kde and .kderc.
Or if that doesn't bring it alive, create a new user and start KDE as that user, and copy the files from that users directory. Then they'll be all fresh and new and untampered.