Snap, crack or pop, maybe

Huddle ender

Shatter

Intermission

With 57-Down, part of a morning routine

Go all to pieces

Bit of luck

Start of a billiards game

Intermission ... or what you can do to the starts of 17-, 24-, 38-, 46- and 59-Across

With 65-Across, go against the group ... or what the shaded squares literally do in the answers to the starred clues