Possible Clues:

• Publication since 1967, and a hint to the end of 20-, 36- and 43-Across
• One without roots lets no girl on if dressed
• Person refusing to settle, a Sisyphean problem
• "Basic Instinct" star Sharon, in a bowling alley?
• First publisher of Hunter S. Thompson's 'Fear and Loathing in Las Vegas'
• Part of Fred and Wilma's car
• Progressive rock music magazine
• Item that gathers no moss, illustrated by the circled letters
• It is said to gather no moss