Oh boy.  A Thursday with some nasty turns.  This is one of those themes that you may catch onto quickly (be sure to read the note at the top of the puzzle), but that isn’t like to be a huge help solving the puzzle.  One theme hint:  When it says “the missing part can be found in four other places in the puzzle,”  this is one of those “think outside the box”  (one of my least favorite phrases, btw) but pay close attention to what’s inside the box (i.e. the puzzle grid).   Even when I was done, I had trouble finding all four spots.  The fact that a couple of the one’s that are missing something work without the extra something weakens the theme considerably IMHO.

One more comment before the hints:  There are is at least one and possibly two Natick’s in this puzzle — places where two very unusual answers cross each other so you pretty much have to guess.  I admit I had to use “Check” in Across Lite several times before I could figure out what the Three pronged fishing spear (It is not anything with TRI in it!), the swimmer, the old guitarlike instrument and the inferior imitator were.  Oh well, there are always days like that.

Now for some specific hints:

1967 Disaster:  Think a cape in Florida that is famous for something other than hurricanes or hanging chads.

Lazy sort:  Think what really lazy people do all day because even being a couch potato is too much effort.

Criticize cattily: 2 words

Unwakeable: 3 words

Steve Martin romantic comedy:  Aren’t all Steve Martin movies romantic comedies?  Anyway this one takes place, as its title indicates in a specific place in the U.S.

Group of whales:  Yeh, I thought it was a POD too, but it isn’t.

Country where marinated bear…:  Do they have that many bears in the Baltic that they go around marinating them?

Serious rap:  Or a description of this puzzle!