check also the Kde Kiosk mode howto and the Kiosk Howto
see the motivations in th Kde Kiosk mode;
The user should not be able to open an interactive shell (Terminal), or run arbitrary commands,
The user should not have a view to the filesystem, so no filemanager,
The user should not be able to modify or create files directly by means provided by KDE (no editor, menuedit, etc.).
and don't forget to disable the SysRq key also
I think it's more about security and restrictions then what distro to use, simply pick the one
you know best.