Add a TextAlignment property to the GridView's AggregateFunctions to set the alignment of the resulting text. 
Apply to both Caption and FormattedValue simultaneously. 
This way we won't have to make custom ItemTemplates for the AggregateResultsList in each footer, when using AggregateFunctions out-of-the-box.

This is reproducible in a hierarchical scenario. The nested gridview loses its selection when its parent row is scrolled out of the viewport.

Update: Before our change the GridViewGroupFooterCell content was right aligned and the GridViewFooterCell content was left aligned. We decided to unify them by setting default left alignment to both. This can be easily modified by changing the Column FooterTextAlignment property to Right or by using the following implicit styles: 

<Style TargetType="telerik:GridViewGroupFooterCell" BasedOn="{StaticResource GridViewGroupFooterCellStyle}">
    <Setter Property="HorizontalContentAlignment" Value="Right"/>
</Style>
<Style TargetType="telerik:GridViewFooterCell" BasedOn="{StaticResource GridViewFooterCellStyle}">
    <Setter Property="TextAlignment" Value="Right"/>
</Style>

The fix is available in R3 2017 of UI for WPF.

The header row (the group headers in a GridView, or a parent row in a TreeListView) stays in the screen while scrolling until all the children rows have been scrolled.

The feature is available in R3 2017 Release of UI for WPF.
Check what's new in R3 2017 here: 
http://www.telerik.com/support/whats-new/wpf/release-history/ui-for-wpf-r3-2017

Currently VQCV caches all the items once they are loaded. In this way the data virtaulization functions only through the first bottom-most item scrolling. The idea behind this item is to make this behavior optional by introducing an alternative mode.

workaround:
public MainWindow()
{
    InitializeComponent();

    this.grid.Loaded += grid_Loaded;
}

void grid_Loaded(object sender, RoutedEventArgs e)
{
    this.grid.ChildrenOfType<Grid>().FirstOrDefault(x => x.Name == "PART_OuterGrid").RowDefinitions[1].Height = GridLength.Auto;

    var cells = this.grid.ChildrenOfType<GridViewHeaderCell>();
    foreach (GridViewHeaderCell cell in cells)
    {
        cell.ChildrenOfType<Grid>().FirstOrDefault(x => x.Name == "PART_OuterGrid").RowDefinitions[1].Height = GridLength.Auto;
    }
}

By default, the RadGridView will expand its rows to fit whatever the size of the text content. If you have a large amount of text with newlines, it essentially renders the grid unusable in this state.

The thread http://www.telerik.com/forums/limit-row-height suggests two workaround: 1) using a converter to remove newlines- this is a bad solution because it means the binding on the column must be one-way. 2) Applying styling to the grid's textblock- also not great because its non-obvious and requires a lot of boilerplate.

My suggestion is two properties on the RadGridView: MaxRowHeight and MultilineRowContentBehavior. This second property would determine what happens when a row has multiline content and would take an enumeration: SizeHeightToContent- the current behavior. SingleLineExpandOnEdit- when displaying, shows only a single line of the multiline content. When editing, expands the TextBox to fit the content. SingleLine- displays and edits the content in a single line.

Current workaround for the affected themes - Define the following control template for the GridViewCheckBox:

			<ControlTemplate x:Key="GridViewCheckBoxTemplate" TargetType="telerik:GridViewCheckBox">
				<Grid HorizontalAlignment="Left" VerticalAlignment="Center" Width="13" Height="13">
					<VisualStateManager.VisualStateGroups>
						<VisualStateGroup x:Name="CheckStates">
							<VisualState x:Name="Checked">
								<Storyboard>
									<ObjectAnimationUsingKeyFrames BeginTime="0" Duration="0" Storyboard.TargetName="CheckedPath" Storyboard.TargetProperty="(UIElement.Visibility)">
										<DiscreteObjectKeyFrame KeyTime="0">
											<DiscreteObjectKeyFrame.Value>
												<Visibility>Visible</Visibility>
											</DiscreteObjectKeyFrame.Value>
										</DiscreteObjectKeyFrame>
									</ObjectAnimationUsingKeyFrames>
								</Storyboard>
							</VisualState>
							<VisualState x:Name="Unchecked"/>
							<VisualState x:Name="Indeterminate">
								<Storyboard>
									<ObjectAnimationUsingKeyFrames BeginTime="0" Duration="0" Storyboard.TargetName="IndeterminatePath" Storyboard.TargetProperty="(UIElement.Visibility)">
										<DiscreteObjectKeyFrame KeyTime="0">
											<DiscreteObjectKeyFrame.Value>
												<Visibility>Visible</Visibility>
											</DiscreteObjectKeyFrame.Value>
										</DiscreteObjectKeyFrame>
									</ObjectAnimationUsingKeyFrames>
								</Storyboard>
							</VisualState>
						</VisualStateGroup>
					</VisualStateManager.VisualStateGroups>
					<Grid Background="Transparent">
						<Border
                        BorderBrush="{TemplateBinding BorderBrush}"
                        Background="{TemplateBinding Background}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        CornerRadius="{telerik:Office2016Resource ResourceKey=CornerRadius}"/>
						<Border x:Name="IndeterminatePath"
                        Width="9"
                        Height="9"
                        VerticalAlignment="Center"
                        HorizontalAlignment="Center"
                        Background="{telerik:Office2016Resource ResourceKey=IconBrush}"
                        Visibility="Collapsed"/>
						<TextBlock x:Name="CheckedPath"
                        HorizontalAlignment="Center"
                        VerticalAlignment="Center"
                        FontSize="13"
                        FontWeight="Normal"
                        FontStyle="Normal"
                        Foreground="{TemplateBinding Foreground}"
                        FontFamily="{StaticResource TelerikWebUI}"
                        telerik:GlyphAdorner.ShowGlyphInDesignTime="True"
                        Opacity="1"
                        Margin="-1 0 0 0"
                        Visibility="Collapsed">
                    <Run Text="{StaticResource GlyphCheck}"/>
						</TextBlock>
					</Grid>
				</Grid>
			</ControlTemplate>
			<Style  TargetType="telerik:GridViewCheckBox" BasedOn="{StaticResource GridViewCheckBoxStyle}">
				<Setter Property="Template" Value="{StaticResource GridViewCheckBoxTemplate}"/>
			</Style>

Fix available in LIB version 2017.2.814.

A workaround it so use a GridViewDataColumn and define a CheckBox within its CellTemplate.

Fix available in LIB version 2017.2.814.

Currently, if the value set to the RowHeight of RadGridView is lower than the Height of the highest cell(or the Height of a Hierarchy defined), it will not be respected. Provide an option the RowHeight to have greater weight than the height of the cell.

Available in LIB version: 2017.2.724

To work this around you can set the EnableColumnGroupsVirtualization to False.

Alternatively you can change the FrozenColumnCount before adding the columns, and reset it once the process is done. For example:

gridTriffDetails.FrozenColumnCount = 0;
 
gridTriffDetails.Columns.Add(newColumn);
gridTriffDetails.Columns.Add(newColumn1);
gridTriffDetails.Columns.Add(newColumn2);
 
gridTriffDetails.FrozenColumnCount = 1;

Available in LIB version: 2017.2.703

Available in LIB version: 2017.2.703