Peter:
I would like to see the Reporting Manager role having full rights to the Reports tab, full rights to the Tickets > Dashboard so that they can create "quick views" of their teams, but then read only when they click on the elements within the Dashboard. This way, they can have full view of the productivity of the team at a glance using the Dashboard, review historic data using Reports, and even drill down to look at possible problems from the Dashboard, but not actually manipulate tickets.
Hope this helps.
-Ryan