Hello Roy,
For a sample project about your first questions you can refer to this forum post:
http://www.telerik.com/community/forums/silverlight/window/how-to-raise-event-for-my-scenario-using-telerik-s-rad-window.aspx. In it is illustrated how to access one RadWindow from another. You can use the same approach to achieve your goal.
As for the second question: unfortunately, this is not a supported scenario by Silverlight. You cannot show a Silverlight RadWindow outside the Silverlight plug-in.
Hope this information helps. If you have further questions please let us know.
Kind regards,
Konstantina
the Telerik team
Browse the
videos here>> to help you get started with RadControls for Silverlight