Expose a property through which the TabContentPopup IsOpen state can be programatically controlled. This feature should allow the implementation of a scenario where the TabContentPopup is opened when hovering over the tab.

Declined: The current API of the RadRibbonView allow the users to control MinimizedPopup. A sample application is attached demonstrating how the Popup can me controlled

Add MouseOver Selection states in the RadRibbonTab control

Decline reason: RibbonView and its elements (including TabControl) are inspired by MS Office products. Since hovering over the selected TabItem in MS Word for example doesn't change its visual appearance it shouldn't in RibbonView as well.
If your project design still requires such appearance then we highly recommend that you edit the Control Template of the TabControl in Telerik.Windows.Controls.RibbonView assembly and add a MultiTrigger Condition (in WPF):
  <MultiTrigger>
                <MultiTrigger.Conditions>
                    <Condition Property="IsMouseOver" Value="True"/>
                    <Condition Property="IsSelected" Value="True"/>
                </MultiTrigger.Conditions>
...
</MultiTrigger>
or add a  <VisualState x:Name="SelectedMouseOver"> to CommonStates VisualStateGroup.

The MinimizedPopup should be closed after clicking on a RibbonControl in the RibbonGroups

ElementName binding is not working in RadRibbonBackstage.

Reason for closing: The ElementName binding in Adorner is not supported and as the RadRibbonBackstage is Adorner it is not working there as well. Due to that framework limitation we cannot fix this issue and we will change the status of the feed back item to declined. You can find more information about the Adorner and its limitation in this article ( http://msdn.microsoft.com/en-us/library/ms743737%28v=vs.110%29.aspx ).

The constructor of the GroupVariantCollection is internal

Reason for declining: The RadRibbonGroup uses the GroupVariantCollection internally and as there is no public property of type GroupVariantCollection there is not need for the constructor to be exposed. Also if the users wants to bind the Variants of the RadRibbonGroups they can use the VariantsSource property which is of type IEnumebable<GroupVariant>.

The MinimizedPopup could be open/closed by using the SelectedIndex property of the RadRibbonView.

A sample implementation could be seen in the attached project.

Add panel element to the TabStripAdditionalContent property. This way it will be easier for the users to add content.

Declined: The existing API for the TabStripAdditionalContent property (of type Object) easily allows the users to customize and insert content depending on their requirements. For instance if you want to use data from ViewModel and list all of its Items you could use the following code:
<telerik:RadRibbonView.TabStripAdditionalContent>
	<ItemsControl ItemsSource="{}" >
		<ItemsControl.ItemsPanel>
			<ItemsPanelTemplate>
				<StackPanel Orientation="Horizontal" />
			</ItemsPanelTemplate>
		</ItemsControl.ItemsPanel>
	</ItemsControl>
</telerik:RadRibbonView.TabStripAdditionalContent>

This issue occurs when the ApplicationMenu is bound. The button in the ItemTemplate of the ApplicationMenu could be both RadSplitButton and RadDropDownButton. Their DropDownContent should not be displayed downwards, it should be displayed in the RightPane ( the Content of the Applicationmenu)

Declined: When the ApplicationMenu is in DataBound scenario the ItemsControl from which the ApplicationMenu inherits automatically creates ContentPresenters for each item and wraps their content. As the ApplicationMenu knows how to manage RadRibbonDropDown/Split buttons you will need to provide one of these containers as direct child of the  menu. You can achieve that using the following code, to show all items as RadRibbonDropDownButton:

public class CustomApplicationMenu : ApplicationMenu
    {
        protected override bool IsItemItsOwnContainerOverride(object item)
        {
            return false;
        }

        protected override DependencyObject GetContainerForItemOverride()
        {
            return new RadRibbonDropDownButton();
        }
    }

We have RadRibbonView. There is some elements in a RadTab, that are inside RadOrderedWrapPanel.
If we set a theme to the RadRibbonView, it is not applied to the elements within the RadOrderedWrapPanel.

Reason for declining: The RadRibbonGroup propagate its theme to its direct children, all nested elements in RadOrderedWrapPanel or custom panel/grid e.t should have set their theme using the attached property telerik:StyleManager.Theme which will be bound to the same theme as the RadRibbonView.

ApplicationMenu do not have keyboard navigation - pressing arrows do not navigate thru the application menu items.
Declined as a duplicate of: https://feedback.telerik.com/wpf/1352753-ribbonview-applicationmenu-do-not-have-keyboard-navigation.

Currently, Title and Description properties are typed to string and the control template uses TextBlock controls to display these properties, I think that only typing these properties to "object", showing them with  ContentPresenters and adding a pair of DataTemplate Dependency properties (TitleTemplate and DescriptionTemplate) would offer an extremely flexibility to this useful control.

Declined: If the users need to transfer object data to the ScreenTip they could use the Tag property(http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement.tag%28v=vs.110%29.aspx)  and bind its value to an custom Implicit style targeting the ScreenTip.