Blimey, few good thoughts there.
1) The Cartier-Bresson cropping thing: Since I have been at this a good few years, I have simply got better and better at framing my shots at the taking stage. This was pretty necessary before autofocus zooms, which make it much easier. I used to work close in with a 35mm f2 lens, and after a while you can see the frame in your mind's eye before you begin to lift the camera. If you spend a large amount of time practising any technique, you will get pretty good, given enough time. Although I have zooms, my favourite lens for this now  is a 35mm f1.4, which allows me to work in very low light and get spectacular differential focus. BUT, you can, of course, shoot rubbish with this lens just like you can with any other...
As for Ansel, he is a true hero not just for his photography, but for his environmental work. I hope I can produce one picture in my lifetime as good as his Mt Williamson, my all time favourite.
The pic above is slightly cropped top and bottom to emphasise the panoramic effect. crude, but effective, je pense...

f8; and be there...