1. You can select multiple checkboxs (square one), But you only select one from radio buttons. (circle one)
2. Why you need a menu or check box to be able to drag and drop? Do you really mean that you want to be able to drag and drop those vectors. You just create ArrorSet in the view and it can be dragged one at a time.
You can also create ArrowSet which is invisible. And when you click on it, make one of the arrow move with the mouse position (You can get mouse coordinate x,y from property of DrawingPanel). Then you have a drag and drop effect.
I believe I can give you better suggestion if you write download in detail what you really want to do.