In SI 5 we have both Grant and Deny permissions. Pay special attention to permissions that start with "Restrict". So if you copy all of the Permissions to the Group Permissions you will actually "Restrict" a lot of SI behavior. This can keep you from being able to add a product to the database or change a price etc.
See page ~34 of the
Installation and Admin Guide for more detail.
Be Careful With Permissions
Linear Mode
