I enjoyed this two part essay on Cheating! You made some very excellent points. In this part I was struck by Devine Destiny and Well That Happened.
What came to mind with Devine Destiny was JKR's Harry Potter series. It would never have been successful if Rawlings had let the fate of the Chosen One remain static. She used many of the suggestions you made and as a result the books became darker and Harry's outcome less sure. It is why the series is not just for children like the eleven year olds I taught when The Philosopher's Stone first came out. Those same added elements have inspired a huge volume of fanfic as fanfic authors pursued what would have happened if...
The other part was Well That Happened. My only comment is to say one of the best books I have read ever is Finding Good Trouble, by @Ronyx. The whole book is based on actions and consequential results that reverberated and built as the story continued. Ronyx has woven a powerful story where actions and dialogue reflect what had happened before that sets up the current emotions, decisions and actions. It felt like a big book, but only used about 70,000 words.
Bravo, Comicality!