What you are talking about sounds very difficult and complicated. Will there be a small set of user categories that will see the same content, or will it be different for every user? If there are not very many user categories, I'd suggest creating a role for each category, and assign the appropriate users to each. Then you can have one page with the instances for each category, and specify that they can only be viewed by the corresponding role. In this case there would be no customization required. Administrator(s) would see and can edit all of the instances for each user group on one page, but users could only see the instances that correspond to their security role.
You can read more about the built-in role security on the Roles and Permissions page.
Hope that helps,