Hi Ramtin, actually, this exact effect where all the core objects are locked and not editable can be achieved using the
workspace hierarchy.
If you build your analytics - data model, metrics, visualizations, dashboards in your parent workspace and then set up child workspaces which inherit all this (and are otherwise empty), the end users of the child workspaces will have read/only access to all these objects within their workspace but will not be able to remove or modify them.
And if they have proper permissions, they will still be able to create their own metrics, visualizations and dashboards based on these core objects within their workspace.