Crossword puzzle clue "word with one or what"

First word across in the first-ever crossword (1913) and the first of a dozen appearances of the word in this puzzle's grid, written word search-style (left, right, down, and diagonally) ... Can you f

Jumble wordplay applied to every Across answer except this one, yielding another word/word form

One word that precedes "pit," one that follows it

One word that precedes "play," one that follows it

One word that precedes "hard," one that follows it

One word that precedes "key," one that follows it

First word of a song whose last word is "Dominum"

Greeting word or parting word