It would help to use RadWindow like System.Window with:
- WindowInteropHelper for correct modal behavior
- Set window in task bar, also set taskbar icon/title
- Use RadWindow as MainWindow in Application (set Application.MainWindow property with RadWindow 

Make it possible to add "No" button to the predefined RadWindow.Confirm dialog without the need of custom Template.

When a modal RadWindow is opened clicking out side of the Window (the overlay) should make a the Window blink and a sound should be played.

RadWindow.Confirm default button is OK, in order to change that presently we have to extract and modify styles, set FocusManager.FocusedElement binding to Cancel and set the ContentStyle property in code. 
It would be much more user friendly if this could be controlled by a simple property.

Available in the 2016 Q1 SP1 Release.

Make it possible to be able to drag the Window not only from its Header. In some cases it is useful to be able to drag the RadWindow from within its content.

As a user of the RadWindow control I want to be able to close it only by setting the DialogResult property without calling the Close method so that I can use it easily in MVVM scenarious.

The default Window control exposes an TaskbarItemInfo (https://msdn.microsoft.com/en-us/library/system.windows.window.taskbariteminfo%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396) which is useful for manipulating the taskbar item of the Window instance.

The property is present, but it is not implemented. 

When creating themed applications using RadControls, the standard Windows MessageBox control looks out of place.  With that in mind, the predefined RadWindows (Alert and Confirm) seem to be natural replacements for a typical MessageBox.  

However, when these dialogs open, they are silent  That is, they don't play any error, warning, or question sounds like the standard MessageBox - which makes them seem "strange" when used as a replacement.

Adding sounds to (for instance) the Alert window is fairly simple and can be accomplished like this:

RadWindow.Alert(new DialogParameters()
{
    Content = new System.Windows.Controls.TextBlock {
        Text = ex.Message, Width = 250, TextWrapping = TextWrapping.Wrap },
    Header = "Update Error",
    Opened = (alertDialog, eventArgs) => System.Media.SystemSounds.Exclamation.Play()
});

Though, it'd be nice if the ability to play a sound was built-in.  I'd suggest that the DialogParameters class used to customize the predefined dialogs be extended to support a SystemSound member of type System.Media.SystemSounds which, if defined, would play the specified sound when the dialog opens.

As a developer I want to be able to open a modal window that doesn't block the thread so that calling thread stays active while the modal dialog is open (like in Silverlight and XBAP). Create a blog post demonstrating how to use the Show method to simulate this behavior.

There should be an easy method to add/override the shadow of a RadWindow. Either via XAML attributes or code behind.

<telerik:RadWindow x:Class="MyRadWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        Header="Settings" WindowStartupLocation="CenterOwner" SizeToContent="True" ResizeMode="NoResize" MinWidth="500" MaxWidth="900"    DropShadowOverride="True" DropShadowOverrideBlurRadius="10" DropShadowOverrideDirection"-90", DropShadowOverrideDepth="3" DropShadowOverrideColor="White">
     
    <Grid>
 
    <!-- UI code -->
 
    </Grid>
 
</telerik:RadWindow>

This is WPF only and not applicable for Silverlight.

As a <role> I want <ability> so that <benefit>.

Provide out of box text wrapping in predefined dialogs.

All Windows messageboxes from Win95 have this possibility. 
Telerik in 2018 does not have this possibility, except through additional templates and additional code. 

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