you have the right idea with the layer cake method that is how itd be done (in pretty much every 2d game regardless of c2 or not) but instead of tryin to make sure you trigger the right animations on all the different parts just each step set those parts animation and frame to the main parts. Then you only have to worry about making sure the main part (body prolly) is animated correctly in your events.
Thinkin about it now you can see why most 2d games dont have a visual gear effect right?