Have you exhausted the permission options?

If you don't give "Edit" access to any users - other than Admin - the actions menu shouldn't display.

However, if you have some modules that need certain permissions you could customise your Containers with some server side code.

For instance - the logic might not be perfect but something like this:

    <% If PortalSecurity.IsinRole("Administrators") %><dnn:Actions .... > <% End If %>

This would only add the actions menu to the control tree if the user was in the Admin role.