Crossword puzzle clue "mark that appears four times in this puzzle hint the baseball player who's the answer to this puzzle uses one too"

Mark that appears four times in this puzzle (hint: the baseball player who's the answer to this puzzle uses one, too)

"Annie" song with the lyric "Too busy / Too crazy / Too hot / Too cold / Too late / I'm sold"

Today, to Caesar—and a hint to the hidden word appearing in this puzzle 15 times (including the one in this answer)

Christmas figure whose prominent feature appears four times in this puzzle

Platform ... or something that appears four times in this puzzle?

Topic of international negotiations ... and a hint to every four-letter answer in this puzzle

Number of times this puzzle's theme word appears diagonally in the grid (to complete the puzzle, shade those words plus the Down answers that begin where they meet)

Appears unexpectedly, and a hint to this puzzle's circles