You can edit the LayoutModeSelector's template to achieve a different look of the control than the default one. In order you want to remove the LayoutModeSelector control from the RadRichTextBoxStatusBar, you should remove that control from the RadRichTextBoxStatusBar's control template.
For your convenience, I've attached a project which illustrates how to do both of the above described control template changes. The changes are made in App.xaml file and a 'NOTE:' comment precedes every change.
Please note, that NoXAML assemblies are used in the project. I'm recommending this approach when you are applying a theme on the controls. You can read more about implicit styles here
In order you are using XAML assemblies in your application, you can use the same edited styles which are used in the sent project as well.
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