13 letters 1980 sci-fi thriller ... or a hint to the answers to the six starred clues Answer: ALTEREDSTATES
13 letters Moves like a buoy in the ocean ... or a hint to the shaded parts of this puzzle? Answer: BOBSUPANDDOWN
13 letters Fairy tale villain associated with the ends of 20-, 27- and 49-Across Answer: THEBIGBADWOLF
13 letters Pirate plunder ... or a hint to interpreting an appropriate number of squares in this puzzle Answer: PIECESOFEIGHT
13 letters Good-looking ... or a phonetic hint to a feature found five times in this puzzle Answer: EASYONTHEEYES