Can you use dijit.getEnclosingWidget to reach the parent data view widget? Perhaps loop on that until you find an enclosing data view?
In the Modeler you can set the form orientation and the label width on a DataView, but there is no widget in the client with knowledge about these properties. These properties only control how the Modeler exports certain CSS classes.
In a custom widget you can only retrieve the form orientation by verifying whether the "form-horizontal" CSS class is present on the DataView. As for the label width, it's exported on the label tag as the "col-sm-X" class (the label also has the "control-label" class).