First of all welcome to the forum Marc. It's going to be great having you on board. Even though I shoot portraits to try to make a little money, shooting landscapes and nature I consider an avocation. Your input will be welcome. I really enjoyed your article "The Mad Cropper" and not that it matters but I agree with you whole heartedly. I tried to add some comments to the images you posted with the article but could not figure out how to do it so I am making my comments here.
Image #1 - I think the crop made a better picture and I can see why you shot that original compostion. I would have done the same thing.
Image #2 - Although I like the cropped image I prefer the original image. The second support in the original image adds a touch of geometrical interest to the image.
Image #3 - no comment
Image #4 - I would have added a black border about 5 or 10 pixels to facilitate framing. It's a great shot. Did you start shooting when the skier went into the jump and how many frames did you squeeze off? Which one in the sequence is this one?

Thank you for your welcome.
I did shoot a sequence of the skier at 8fps with the Canon 1d M2. This is the third exposure. I think you have a good point regarding the cropping of image #2 and I thought about that as well as the fact that by cropping it the way I did placed the other post in the center. However, by cropping it the way I did the man in the corner becomes a more important subject than the post which was cropped out, so I thought!