Th attached gif file illustrates the desired behavior which is supported in the MS MenuStrip. 

Introduce menu merge when the MDI children are in RadDock

Improve the extensibility of RadMenuItem to allow easy layout modifications.

Example: http://www.telerik.com/help/aspnet-ajax/menu-items-xml.html

Examples: http://www.telerik.com/help/aspnet-ajax/menu-data-binding-overview.html

RadMenuItem should be able to be as wide  as the Image in it, if there is not text.

Currently RadMenu wraps its items when there is no enough space in the parent container. A possible alternative would be to implement scrolling.

For RadMenu there should be a property which determines whether the accelerator keys are underlined even when the RadMenu is not focused. The available options for that menu should be Yes, No and WindowsDefined

Add functionality (DropDownNeeded event for example) for load on demand for child menu items in RadMenu.