Light - like sausages?

I have just read the article in New Scientist about twisted light. It needs re-reading. https://www.newscientist.com/article/mg22429954.600-twisted-light-sends-mozart-record-distance-through-air/

It got me thinking about the dual nature of light- waves and particles. This article does not mention the particle nature of light. But consider that waves are not light travelling in a sinusoidal path, but really a measure of the magnitude or density of the light at that point. That's where sausages come in. A stream of sausage meat coming out of a machine has dense bits which are the sausage and is then squeezed down to nothing  and rises again. Now if the contents of this are particles, it means that at high amplitudes of the light wave, we have a high density of particles.

Another  aspect of the wave nature of light is that if light travelled in a wave motion, it would be travelling faster than light.

How can I consider the varying density of  light particles in the dual slit experiment?

Also have to consider how this fits in with polarisation and phase shifting. Colours of light are due to the frequency of the waves,

Thinking about phase, this article does not make it clear, actually it confuses the issue, about the form of phase shifting that occurs.  One type is horizontal, where the peak arrives at a slightly different time and the other I'll call angular, where the wave is at a different angle for the reference wave.