If you click and drag these (with the Arrow - your pointer) you will see you have created a new image, about the size of the area you masked, with a nice featherd edge, fading off into transparency. If this is not the effect, or amount of fade, or enough picture showing, be ...
Objects are the equivalent in Photopaint. Under View>Dockers menu there should be an Object Docker. It will put a window on the side of the screen (which can be moved around). It controls lots of aspects of objects (merge, order, lock transparency). Good tool. As for paths, what are...