What a delightful puzzle, with some truly novel features -- and although at first glance it looked like it was going to be fiendish, I found it yielded to quite a bit of logical deduction which helped me figure out some of the trickier clues. Great fun for the Christmas-NewYear interstix.
Re quixote@56 and others worried about the first word of the message, I have finally tracked down actual video clips of the speaker delivering the message and it really is exactly as the puzzle presents it. However, like many famous quotes (Play it again, Sam -- Luke, I am your father) it seems to be routinely misquoted with an alternative first word, which makes googling for the message doubly difficult until the speaker's name is uncovered.
I do have a couple of parsing queries just to put my mind at rest. I know 39a has been mentioned already, but I understand the answer and the definition and the alteration and it's just the wordplay I don't see -- where does the soft hat come in? And 47a I obviously have the answer and I know the clue type but again I can't see the wordplay. And 45a just befuddles me -- the wordplay is fine and I have the answer but while other clues of its type I can see the logic (and laughed out loud at some of them -- thanks Lionheart!) I just can't see why this would qualify. Any hints people can give to nudge me to satisfaction would be greatly appreciated.