You can add text to connectors, as well as to other objects. See examples below. You can use connection points for glueing connectors and other objects to them. You can add as many connection points as you want. Note, that a connection point may belong to an object even when positioned outside the object.
Control handles make an object behave in a special way.
Many library objects have control handles, which you drag to adjust the object in a specially programmed way. With the Rectangle tool - draws a square. With the Ellipse tool - draws a circle. This may be useful for resizing proportianally when the Rotate tool is on and corner handles can't be used for resizing as they normally can. Edit Text tool.