"This type of page is not served" - backend users

1.  In the backend I have a role (marketing) that is set to only be able to edit/upload to a particular library (marketing files).  For a different library (operations files) they are denied to "View this library".  So, upon landing on the Documents and Files page, the marketing role user will only see their library (marketing files) listed in the right column.  However, there is also the listing of all files in all libraries on the page. The problem is - if they click on something they are not allowed to do (like delete a file in the operations files library) it throws the page with the error This type of page is not served. Is there a way to prevent this or does this error page need to be the same as the page set in the web.config for the whole site? 

2. With the permissions set as above, I am using the library list control for a front end secure page. On this page I have both the marketing files and the operations files libraries.  Upon a user login, I DO want them to see and download from both libraries and they can!  So, the library permission of "View this library" doesn't look like it is honored in the download list control?  
What is the relationship between the permissions set in the back end for libraries versus the download list control on a front end page for each of those libraries? Is this the way it is supposed to work?

Version - Sitefinity 4.4.2117.0 
Thank you. 

I kind of figured out my answer.
The back end and front end libraries / files follow the same permissions (using the same log in credentials) duh. If I denied access to the libraries in the back-end so they can only see and  upload to their own library, I would need a different front-end login with credentials to see all the specified libraries but not be allowed as a backend user.

EXCEPT if I  Deny a role for "who can view this library" in the back-end, it still can be viewed by that role in the front end...(?)