There's a lot of wisdom in this post. I've only been raising chickens for a little over six months, but I've already experienced much of what you've described here.
It seems to me that chickens have individual personalities...just like dogs....just like humans. You can raise all of them the same way and yet some will be incredibly sweet and others will be nasty. The trick for me has been learning when to respect those differences, and when to just throw in the towel and cull. That BR rooster...I tried many techniques with him to no avail. When I went out to collect eggs four days ago and turned to find his spurs coming at my face I'd finally had enough. That wasn't charging but an all out assault for no apparent reason. He had to die. By comparison, I can do whatever I want to my black NN, Heisenberg, and he's never shown an ounce of aggression, but I would never dream of handling my NN "Goldie" that way. He doesn't bite or charge, but he's also not that affectionate. I'm okay with that. He respects me, never shows aggression towards me and takes good care of the flock.
I'm actually in the process of incubating some of my BR rooster's offspring. I'm curious to see what their personalities turn out like...if any of them will be keepers or if they'll adopt his temperament. I originally wasn't going to hatch any eggs fertilized by him but my own curiosity got the better of me (as well as my Psych degree). I want some first-hand experience with the nature vs nurture via and chicken world. All the books I've read, research I've done...it's all pedantic. Nothing can beat "living the experiment".