1.I liked drawing from the photo - it was easier for me than drawing from a painting. or drawing from life. Could see details. But is 2 dimensional. Nothing comes easily for me when drawing or sketching. I will be 79 in a couple of days and I have always had trouble with spatial perception and transferring what I see to paper. I think I am finally beginning to learn how to look at something and figure out how the parts make up the whole.
2.I probably would not have noticed the ruffled feathers on the belly, the layering of the wing feathers, and the slight shadowing on the far side of the throat. I think it would make a difference. Your sketch would look too flat if it did not indicate this dimensionality. I can see why some journalists choose to have small side boxes showing details like the above.