Well if water didn’t have its unique properties of cohesion and adhesion we likely wouldn’t be here anyways.

The sound source is moving in the above scenario relative to a stationary object. I’m not saying you’re wrong but that was my thinking.

I think eventually you reach a point where previously played notes would lose all of their energy, meaning there’s probably an upper limit on how loud it would get for an observer at the end. Something something Doppler effect.