In order to prevent the selection in RadPanelBar you can subscribe for its PreviewSelectionChanged event and handle it.
sender, SelectionChangedEventArgs e)
However, disabling the visual feedback of the selection feature won't be such straightforward task. To do that you can extract and modify the template of the RadPanelBarItems and hide their selection and mouse over visuals. You can take a look at the Editing Control Templates
help article which will be useful for this case. Keep in mind that the RadPanelBarItem is a hierarchical control and you will find few templates in its style. In other words you might need to modify the selection visuals on few places.
I hope this information is useful.
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