Physics is needed to know how things work correctly, so what you draw will look like it will work if it is real. If you study colour, you are basically studying how light works, and that is physics. When you learn to draw a person, you may come across terms like centre of gravity, which is basically part of physics.
So... yupe. You dont need to study physics but you need to know them to make your art better.
Hm.... I dont see it that way. I am not an analytic thinker. Those note might just be random physics stuff that has nothing with the mech. Or that might be just notes he is taking in class, and then got bored and started drawing. Though seeing that this is obviously a sketchbook this may not be the case.
I tape a piece of drawing paper over my Intuos3 to help protect and give me a more authentic feel when drawing. I find it way more satisfying than drawing on the standard active area. You just have to replace the paper fairly often, as it gets ruts and gouges in it.