Theme Hint:  Well, remember what today is (or was, if you’re doing the puzzle on a future day).   There’s a “meta” puzzle here — a puzzle within the puzzle — but I didn’t figure it out…and didn’t really care.  In terms of solving the puzzle itself, though, as soon as you get one you’ll get the wordplay trick that is in every starred clue.  It isn’t a very dramatic trick.  Remember title, “Special Features,” because all the long clues’ word play transform the same type of “thing”  (also hinted at by the  “key” clue (115-Across).

10 hints to non-theme answers:

41-Down Airplane area:  Or:  A kind of fever (particularly common among people who live in Northern climes as winter drags on.)

66-Down Nook:  Or:   Nook’s partner

68-Down Weekly bar promotion:  I guess you wouldn’t find these much in gay bars.

78-Down Solo companion:  A hairy companion, at that.   Don’t get hung up on the apparent paradox

26-Across Steaming beverage:  Think Starbucks

113-Across Kind of bean:  Or:  Car famous for its exploding rear end

25-Across It comes from the heart:  Literally, not figuratively

72-Down Wasn’t exacting:  2 words

72-Across Device Professor X wears over his head in X-Men:  He’s a real brain!

119-Across Nonstop:  2 little words