The LeaderNote object has a property called 'DimensionStyle', which is where you would set its Style, and it has a property called 'Layer', which is where you would set its Layer. The LeaderNote object can be found under DrawingDocument.Sheets.Item(1).DrawingNotes.LeaderNotes.Item(1).
The PartsList object has a property called Style, and a property called Layer.
Section lines are usually SketchLines within a DrawingSketch, belonging to a DrawingView (DrawingView.Sketches), where the geometry has been made visible outside of the sketch, and assigned to a layer. Then the SketchLine objects each have several properties for things like LineType , LineScale, LineWeight, OverrideColor, and so forth, but all those aspects could also be set by the Layer itself, because the SketchLine objects also have a property called Layer. There is actually a sub-type of the DrawingView object called SectionDrawingView, and it does have a property called SectionLineSketch, which is most likely where you would obtain this specific sketch.
I am not sure what you mean by detail view call-out curve, but it sounds like that would also be geometry within a drawing sketch, which could be controlled much the same way as the section lines above. There is a special sub-type of the DrawingView object called DetailDrawingView. And that object does have a property called BoundaryLayer. That may also be what you are looking for.
Wesley Crihfield

(Not an Autodesk Employee)