I need to create a role that admin can only edit attach products to category nothing more. In Permission/Role i can see only "Manage Product" to enable/disable but it is too big scope. How can I only allow admin to manage category and hide everything else? The only way is create a new grid for adminpanel?
The only way to do this is to reimplement the Magento catalog product edit page with new ACL checks for this area and the other areas. The simplest way would be to have one ACL check for the category content, and one for all the other content.
It's definitely doable, but isn't a small project.