"color theory" Colors have weight in their value. Too close a shade and the work is muddled. Just the right color in the right place and you have vibrancy and motion. You apply a filter with B&W to approximate color weights. Without the filter the image is/can be muddled. Apply a red filter and green falls back
apply a green filter and green comes to the front ..or you could skip that chapter and just say the tones separate in much the same way as they do in color for us.
I don't believe there is any difference. Using black and white film is just a new way of seeing color. I often take Color photos and simply desaturate em to see if there is any difference ..none. A good color photograph will make a good B&W same as a good color painting will make a good B&W painting. There is a reason why there are filters and that reason is "Contrast"
Same reason for why always using a dark red filter isn't the best thing to do ..eventhough it seems "really cool" to do just that.
B&W gives you the ability to paint a little bit and color is more like finding a painting