You can drag and drop a map from the Catalog Pane onto a layout view. You should also be able to drag and drop a feature classes and layer files into an activated map frame. I'm not exactly sure when this functionality was available, but I tested on 2.2.1. Another thing to keep in mind about adding layers into a legend - the layer must be from the same map/map frame that the legend points to. You will not be able to add a layer from map "A" to a legend that references map "B".
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