Instead of using the focusmap property you need the pagelayout property to draw too. That means adding the graphic polygon element to the layout instead of the map. PageLayout can be cast into an ActiveView and you can deal add the polygon element and export that view. That should work ok but you will only see the rectangle if you switch your ArcMap view to layout.
There is another way to do what you want with the data frame view (elements drawn to the map.) In ArcMap, right click on the dataframe name (layers by default.) Under labels, select label weight ranking. In the label weight ranking form, the first layer should be "default", set the feature weight to none. Your labels should appear through the polygon even if it has a fill. If your polygon is not drawn to the default annotation graphic layer, you will need to set the feature weight of whatever annotation graphic layer it is in.
The problem is that a map annotation graphic layer acts a lot like a database annotation layer. Annotation and labels have weights to prevent them from overlapping. For most text annotation and text within a box (rectangle) you want this. In your case you don't, so you have to change the default properties. If you have elements in your graphics that you don't want to labels to overpost and so you do, you can create a new annotation group from the drawing menu of the drawing toolbar and set different properties.
