OK...

Your cupsd.conf  configuration is a bit false and not complete. 

Listen localhost:631 should be left as it is or change localhost to your server ip address. In your case that would be Listen 192.168.0.100:631

And you should allso add "Allow 192.168.0.70" under "Restrict access to the server pages...". If you don't add that Home page, Documentation, Help, colors and button images will not be available when you log in on cups admin gui. You will only have access to admin pages.