How to Setup Multilingual Section (Not Site)
Yes you are right, internationalization is made for a full website in several languages. But you will be probably be able to achieve what you want by using views everywhere.

Instead of displaying a classical node, you will display a view with 1 node inside a block, inside a panel (probably).
You setup your view to use the language your want and the content type you want, that should do the trick. It's a bit different approach if you compare it with the standard drupal approach of creating page.

To ensure that the node page is not accessible, you can use the module node page disabled. 

I hope it helps

Cheers