A very nice summary of engine anti-ice usage. The only thing I would add is the warm air used for the nacelle and spinner cone anti-icing comes from bleed air off the compressor. So if you use it when it is not needed, it hurts the overall engine efficiency.
Since spinner cones has turned up twice in this thread, how the heck do you plumb on-off bleed air into a spinning cone on the front of an engine?