Question: Were the scientists involved really concerned about igniting the atmosphere?
Question: Was Paul Giamatti's lazy eye achieved through practical means or CGI? If it was practical, how exactly did they do it?
Answer: The best information I read was from an online "People" magazine article. Actor Paul Giamatti says he is sworn to secrecy on how the lazy eye effect was achieved, other than to say it was "movie magic." I hope someone finds additional information and shares it here, as I'd like to know more.
Question: When Lucy Gray tells the peacekeepers to "give her a minute," why do they all back off and let her sing instead of carting her off to the train? The police basically take orders from her, and I'm pretty sure singing would have been classified as rebellious behavior. Was it because she had to have protection now that she was one of the chosen Tributes?
Answer: The Peacekeepers were likely a little subdued because a large crowd is watching and everything is being aired on live TV. They would not risk inciting a riot. The Peacekeepers are low-level Capitol servants, so they may be concerned about the repercussions to themselves if they are overly rough with a female tribute. Allowing her to sing also makes for better TV, and the Capitol is trying to increase viewership.
Answer: The short version is "no, not really". Much like in the film, the possibility was considered, a lot of calculations were done, and it was agreed by everyone privy to them that the chance was basically zero. Also like in the film: "what do you want from theory alone?" - it couldn't be guaranteed to be absolutely zero, but then the chance of almost anything happening is never absolutely zero. A 1946 report by three of the scientists stated: "whatever the temperature to which a section of the atmosphere may be heated, no self-propagating chain of nuclear reactions is likely to be started. The energy losses to radiation always overcompensate the gains due to the reactions."