[jasonwatkinspdx]

You are way over complicating this in avoiding just googling the actual definition of sound in a physics context. It's acoustic waves in a medium. Acoustic waves are adiobatic compression/rarefaction waves.

All your examples are just sound. There's no difference if the medium is all gas, all tennis balls, or a mixture of both along with some very confused corgis.

The medium, and whatever objects it exists as, are not sound itself. The notional particles of sound waves are called phonons.

Propagation of transverse waves in the electromagnetic field is what we call light, radio, and other electromagnetic radiation. There's also constraints of symmetry for how the electric and magnetic portions of the field relate to each other. The notional particles of these waves are photons.

To address your last point, it would help to stop thinking of waves as platonic objects with their own independent existence as objects, and instead see them as patterns of activity/interaction within ongoing dynamic systems.

All of your examples are simply sound. There's no confusion in this. And yes the definition of sound still requires a medium.