I don't know if this is direct or helpful, and I don't know much about the default kiosk mode but past discussion indicates it doesn't go far enough, but through various intensive customizations of the browser you should be able to achieve what you want, while locking end users out of the ability to change settings.
Note Fred's and other's talk in these threads:
http://kmeleonbrowser.org/forum/read.php?1,104622
http://kmeleonbrowser.org/forum/read.php?1,80705,80711
Note Fred's kiosk version:
http://kmeleon.sourceforge.net/wiki/UKmeleon#km18124cd