The five most popular questions about the content of 'One Tough Customer' focus on: 1) How does Dale Earnhardt's pursuit of his eighth championship and Daytona 500 win unfold in this episode? 2) What challenges does Dale face from the younger generation of drivers during this period? 3) How do the family dynamics evolve as the Earnhardt children begin racing careers? 4) In what ways does Dale's fame and fortune impact his personal and professional life in this episode? 5) How does the episode portray the balance between Dale's racing ambitions and his role as a father to his racing children? These questions arise from the episode's focus on Dale's career peak, competition, and complex family relationships as described in multiple sources.