I don't see why there should be any extremes to the spectrum. I would assume that it would be infinite, or close to, with waves ranging from near zero energy to near infinite energy.
I am not in disagreement with either of you, I was just supporting your argument that certain wavelengths of electromagnetic radiation have tendencies to manifest themselves in different ways.
Yeah, you don't hear people talking about 'photons of radio signals' because at (comparatively) low levels of energy like those used by radio, the wave-like properties of the spectrum are the dominant properties.