First, sorry for the delayed answer. We have been busy with the Q1 release. Your feedback is welcome!
Now, the DragDrop:
It is best not to set drag/drop properties in the constructor of the root visual element since the DragDrop needs the root visual element for initialization.
Also, the drag does not go very smoothly, because the path is set as a drop target, while it is best to set the canvas as a drop target.
It seems that the path will always return it's actual size as (0,0) which is not very helpful. This is why the path will always appear to be dragged by its lower right edge. I guess that it is best to calculate its size as you create it and then refer to it as you drag it.
the Telerik team