Understanding the right hand rule is essential to fully understand the relationship between electric charge and magnetism.
The electric field and magnetic field are always orthogonal. That means they must be oriented at 90 degrees to each other. Yes, the sign does matter.
If you look at how solar particles interact with the Earth's magnetic field at the poles, you will notice that you get Aurora displays that appear to circle the magnetic pole. That orientation is the right hand rule in action.
When a charged particle encounters a magnetic field, it encounters a force which causes it to rotate perpendicular to the magnetic field. For the north pole, the particles rotate clockwise. For the south pole, they rotate counterclockwise.
Another interesting presentation.
I was wondering when you showed the PC fan if you were going to address brushless vs. brushed. Glad to see you did. Discussing the two different motor types isn't trivial, which made the video that more impressive.
Did you take a Dremel to those motors to get the cut-away view? That was an awesome way to see inside of them!