With regard to the wave/particle duality of light, does Big Bang red shift affect both the frequency of light waves, and, the frequency of individual photons? I assume that the e=hf formula relates to individual photons, and not to light waves too?
Yes it affects both. If you treat light as waves then the wavelength from a source at a redshift $z$ is "stretched" by a factor of $1+z$.
Photons emitted from a source at redshift $z$ have their energies reduced by a factor of $1+z$.