I'm guessing the first one is some kind of art, or maybe part of a water wheel??
Hard to say. All of them look rather precarious, and as you said, 'stay out of the way and don't follow too close'. Kind of nutty from the safety standpoint, but I suppose efficient and necessary in their world of making a living.

Thanks for the great photos of a slice of life where you live. Just discovered you, Looking forward to more.