Regarding the flare tubes, think about having to land in Paris or somewhere short of that in the dark. That is why they needed them.
Just watched the Spirit of St. Louis last night and again today on cable--what a story! A year after Lindy's flight, 4 men flew a used Fokker trimotor from Oakland CA, to Hawaii, then on to Fiji and finally to Australia. Think about trying to find Hawaii or Fiji with the navigation technology of 1928. Fiji is is tiny compared to Europe. The men were Sir Charles Kingsford-Smith, another Aussie (Ulm) and two Americans (navigator and backup pilot). See this link for more info.