In 12.1, we don't have the ability to disable Email/Saving/Exporting of Reports in any of the Admin Options. We also need to be able to disable the email/save/export options from the Reports Menu drop down. This is a Business Requirement.
In 11.5, we have the ability to disable Email/Saving/Exporting of Reports.
These choices are role associated with the 12.1 version of Web Viewer. To get to them, start under the Administration tab and select Role. Then select the Role where you want to control the actions (e.g. Default User). Finally, click the properties tab and you should see the options you're after.