Thank you for getting to us about this at first glance strange issue.
You have found right that if the ImageEditorUI's Name is ImageEditor, the buttons for the tools and commands of the editor will be disabled. This is caused by the fact that the Name of the ImageEditor in RadImageEditorUI's default template is exactly "ImageEditor". For some reason this results in incorrect behavior in Silverlight as if the UI tries to find the tools and commands in its own properties instead of the editor's.
This does not seem to be a bug in our code and the problem seems to be in the fact that in Silverlight the scope of the names is different than in WPF (where the same case works correctly). A Name is needed in the template, so that the binding between the ImageEditorUI and the ImageEditor can be successfully resolved and there will always be a name that results in this behavior.
Please, change the name of RadImageEditorUI to resolve the issue and let us know if you have any other comments or observations.
All the best,
the Telerik team