No to both of your questions.
You could try to assign a solid white background to your labels though. (This way, it looks like the line right before the label and continues right after.)
Another option would be to specify a preferred placement to the left or right of the edge for each label (see option "Preferred Placement" in the properties view) and arrange the graph with an algorithm that supported integrated edge labeling. (For example, the hierarchic layout offers this, see option "Edge Labeling" on tab "Labeling".)