Now we have better ideas about how electricity works, we tend to talk about current as a flow of electrons, from negative to positive, in the opposite direction to the conventional current. When you are trying to figure out the rotation of a motor or a generator, be sure to remember that current means conventional current and not electron flow.
Bonding should be by the widest practical means. Wide cable tray is effective when it is made of zinc plated steel and carefully bonded at the ends to control panel and motor frame. Zinc plated sheet steel channel is also effective. The fact that the width is folded into a U shape does not matter. A closing lid helps. Solid steel conduit bonded at both ends is effective. The spiral construction of flexible conduit makes it less attractive for RF shielding because the spiral shape forms an inductor, even with partially shorted turns.
As a technician, I naturally look at things from a nuts & bolts perspective. As technicians, we understand objects and assemblies. We understand how things come apart and go back together. Is not this what Einstein and Ohm did? They figured out how "it" comes apart, which led to the ability of others to put "it" back together.
Suppose you take a length of ordinary wire, make it into a big loop, and lay it between the poles of a powerful, permanent horseshoe magnet. Now if you connect the two ends of the wire to a battery, the wire will jump up briefly. It is amazing when you see this for the first time. It is just like magic! But there is a perfectly scientific explanation. When an electric current starts to creep along a wire, it creates a magnetic field all around it.