Yeah, Reinhardt does have some good ideas, I like pretty much all of them. But he doesn't mention anything about the actual riding.
I think it may have been mentioned before, but the idea of using the A & D keys as spurs, or probably knees as these are supposedly well trained horses. So tapping A and D together will make the horse run straight forward, but hitting D more often than A will cause a left veer. To slow down its the same thing, but hit S as well. So if you're at full speed and you want to turn right, you'd hit S and D together. So it would be less like a motorbike and more like a tank (with its two treads functioning independently).