The fact that there was no obvious connection between the extra word in 11d and the main permutation of the six letters led me to think that the extra word was the key to the whole puzzle, but it seems to be a red herring.
I think 40a is a poor clue in a puzzle like this. I thought of LOOSING yesterday but rejected it and have been searching for something better ever since. I also thought of the aforementioned drama but rejected that because it's been done recently and there was so little in the puzzle to lead to that. All but one of the extra words seem to be completely irrelevant.
Perhaps I've made a mistake, but I cannot see the thematically modified author anyway in any direction, diagonally, vertically or horizontally, or is it a non-linear representation?. I can trace the first name but that may be accidental.