Hi Flowgun, try pasting this in to the "Command" part of a shortcut key:

script: var selected_objs = moi.geometryDatabase.getSelectedObjects();
if ( selected_objs.length == 0 )
{
	/* If nothing selected, select all curves */
	moi.geometryDatabase.getObjects().getCurves().setProperty( 'selected', true );
}
else if ( selected_objs.length == 1 && selected_objs.numBReps == 1 )
{
	/* 1 solid or surface is selected, select naked edges */
	var obj = selected_objs.item(0);
	obj.selected = false;
	obj.getNakedEdges().setProperty( 'selected', true );
}
else if ( selected_objs.length == 1 && selected_objs.numFaces == 1 )
{
	/* 1 face selected, select edges of face */
	var face = selected_objs.item(0);
	face.selected = false;
	face.getEdges().setProperty( 'selected', true );
}
else if ( selected_objs.numEdges > 0 )
{
	/* If any edges are selected do loop selection */
	moi.geometryDatabase.selectLoop();
}

- Michael