Possible Clues:

• Criminal oafs without fear getting one in an uncomfortable situation (1,4,3,2,5)
• Premise of many comedies
• Cod in chipper is completely unsuitable to the environment it finds itself in (1,4,3,2,5)
• One no longer in his comfort zone
• Unsustainable cod in chipper perhaps is completely unsuitable to the environment it finds itself in (1,4,3,2,5)
• Crocodile Dundee in Manhattan, e.g
• Description of an eel taken from Okeechobee Lake (1,4,3,2,5)
• Misfit ... or what you get after the sequence described by the ends of 17-, 21-, 57- and 63-Across?
• Flounder in chipper is at odds with that particular environment (1,4,3,2,5)
• Premise of many sitcoms