RE: Prevent browsing the documents folders.
The only way I can imagine achieving this is to remove the link from the standard centers but I cannot find a way to do that.
What you are asking for is not possible. They either have access to view files or they do not.
You can limit their ability to see *other* folders by restricting the audience of the folders – but if you want the user to be able to see the document, they must have access to browse for it in the file cabinet.