Add an ability for the user to select a full column (the SelectionUnit should be Cell and the SelectionMode should be Multiple or Extended). 

Consider this behavior in regard with the sorting of the column.

As a workaround, the Path with the PathGeometry setter in the style can be replaced by a RadGlyph with a pin icon. The IsPinned Trigger in the style can be replaced with a DataTrigger to the parent row's IsPinned. Here's an example of the updated style for the Fluent theme:

<Style x:Key="GridViewPinButtonStyle" TargetType="grid:GridViewPinButton">
        <Setter Property="PathStyle" Value="{StaticResource PinUnpinPathStyle}"/>
        <Setter Property="Foreground" Value="{telerik1:FluentResource ResourceKey=IconBrush}"/>
        <Setter Property="MinHeight" Value="28"/>
        <Setter Property="MinWidth" Value="22"/>
        <Setter Property="IsBackgroundVisible" Value="False"/>
        <Setter Property="Command" Value="{x:Static telerik:RadGridViewCommands.TogglePinnedRowState}"/>
        <Setter Property="CommandParameter" Value="{Binding}"/>
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="BorderThickness" Value="0"/>
        <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
        <Setter Property="VerticalContentAlignment" Value="Stretch"/>
        <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
        <Setter Property="IsTabStop" Value="False"/>
        <Setter Property="Padding" Value="0 0 2 0"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="telerik:RadPathButton">
                    <Grid Background="Transparent">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="BackgroundVisibility">
                                <VisualState x:Name="BackgroundIsHidden">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="OuterBorder" Storyboard.TargetProperty="Visibility">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Collapsed</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="BackgroundIsVisible"/>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Border x:Name="OuterBorder"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                BorderBrush="{TemplateBinding BorderBrush}"
                                Background="{TemplateBinding Background}"
                                CornerRadius="{TemplateBinding CornerRadius}"/>
                        <telerik:RadGlyph x:Name="UnPinIcon" Foreground="{TemplateBinding Foreground}" FontSize="16" HorizontalAlignment="Center" VerticalAlignment="Center" Glyph="{StaticResource GlyphPin}"/>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Foreground" Value="{telerik1:FluentResource ResourceKey=AccentMouseOverBrush}"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="True">
                            <Setter Property="Foreground" Value="{telerik1:FluentResource ResourceKey=AccentPressedBrush}"/>
                        </Trigger>
                        <DataTrigger Binding="{Binding IsPinned, RelativeSource={RelativeSource AncestorType=telerik:GridViewRow}}" Value="True">
                            <Setter TargetName="UnPinIcon" Property="Glyph" Value="{StaticResource GlyphUnpin}" />
                        </DataTrigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

ArgumentException: 'RadGlyphExtension' is not valid for Setter.Value. The only supported MarkupExtension types are DynamicResourceExtension and BindingBase or derived types.

StackTrace:
   at System.Windows.Setter.Seal()
   at System.Windows.SetterBaseCollection.Seal()
   at System.Windows.Style.Seal()
   at System.Windows.Style.Seal()
   at System.Windows.StyleHelper.UpdateStyleCache(FrameworkElement fe, FrameworkContentElement fce, Style oldStyle, Style newStyle, Style& styleCache)
   at System.Windows.FrameworkElement.OnStyleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue)
   at System.Windows.FrameworkElement.UpdateStyleProperty()
   at System.Windows.FrameworkElement.OnInitialized(EventArgs e)
   at Telerik.Windows.Controls.RadButton.OnInitialized(EventArgs e)
   at Telerik.Windows.Controls.RadPathButton.OnInitialized(EventArgs e)
   at Telerik.Windows.Controls.GridView.GridViewPinButton.OnInitialized(EventArgs e)
   at System.Windows.FrameworkElement.TryFireInitialized()
   at System.Windows.FrameworkElement.EndInit()
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.InitializationGuard(XamlType xamlType, Object obj, Boolean begin)

Setting the theme via the StyleManager.SetTheme(control, theme) method does not style the cell as expected when a CellStyle is defined for its parent column.

The current workaround is to explicitly set the theme via the style:
<Style x:Key="BlueCellStyle" TargetType="telerik:GridViewCell">
		<Setter Property="Background" Value="PowderBlue"/>
                <Setter Property="telerik:StyleManager.Theme" Value="VisualStudio2013" />
</Style>

The current workaround is to set the FontSize of the underlying RadComboBox explicitly:

		<Style x:Key="RedCellStyleStyle" TargetType="telerik:GridViewCell" >
			<Setter Property="FontSize" Value="25" />
			<!--workaround-->
			<Style.Resources>
				<Style TargetType="telerik:RadComboBox">
					<Setter Property="FontSize" Value="25" />
				</Style>
			</Style.Resources>
		</Style>

Currently I am using row selection for my readonly grid. There is a cell highlight that shows which cell the user has selected.  I would like to disable that highlight so that the row selection looks consistent no matter where on the row the user clicks.
(Copied from: 
http://www.telerik.com/forums/disable-selected-cell-highlight

See this link for more details:  http://www.telerik.com/forums/how-to-remove-focus-rectangle-from-selected-cell#9GAEx-HPN0C_qOGAsXY2PA   )

This should be possible without adding 200 lines xaml code. Just expose the CellBorderBrush Property so we can easily set it to transparent

Grouping of columns in RadGridView by using a ColumnGroupDescriptor in XAML does not work when ShowGroupPanel is set to False and there is a RelativeSource binding in the ColumnGroupDescriptor.

Check Demos >> GridView >> Hierarchy

First HeaderCell should be aligned with the first cell in the gridview. You can find a screenshot attached.