Crossword Puzzle Optimists keep them alive

Clue: Optimists keep them alive

Instruments for keeping up with the Joneses? (STATUSCYMBALS with 13 letters)
A Dorsey theme song (MARIE with 5 letters)
Campus list keeper (DEAN with 4 letters)
Possible theme for this puzzle (SIDEKICKS with 9 letters)
Puzzle theme missing? (PARAGON with 7 letters)
Noted list keeper (SANTACLAUS with 10 letters)
1996 Robin Williams film, and a hint to this puzzle's theme (THEBIRDCAGE with 11 letters)
Physicist's theme song? (ATOMICNUMBER with 12 letters)
This puzzle's theme (e.g. ANAGRAMS with 8 letters)
Watch keepers (FOBS with 4 letters)