Hi Ian,
As far as I am aware, the Report Designer is where the reports can be generated from so having a Designer license means the user can alter rows, columns, etc..
The only way I can think of would be to give them the Designer License and password protect all of your rows, columns and trees.
This may cause more problems though as anyone who is allowed to update them would need to enter a password everytime they opened one. It also means that the passwords need to be maintained; although with Management Reporter storing it's backend on SQL Server this may not be the problem it was with FRx and it's Access database..
Ian