Possible Clues:

• Fruity pastry made by a movie boxer?
• Inauspicious outset
• Bumpy beginning ... or a hint to 18-, 24-, 36- and 52-Across
• Inauspicious beginning
• Surprised reaction from Bullwinkle’s bud?
• Opening of an Oscar-winning 1976 movie?
• It's the opposite of a flying one
• 1976, for Stallone's rise to stardom?