8.3 -- "Middle Plantation" = Maryland

8.5 -- Greenpeace

10.1 -- John Cardinal Spellman (presided at JFK's funeral) [possible alternate answer: Leonard Bernstein, who composed a Mass, and may have done so in honor of JFK]

10.7 -- Orson Welles, for Citizen Kane

11.1 -- The Great Fire of London

11.3 -- Rome (the alleged "imperial arson" was Nero)

11.4 -- The Reichstag Fire

Of Question(s) #12, the closest I can get is a guess at which sport, which may provide clues for others more keen on those topics:

12.4 is golf
12.7 is tennis
12.9 is (I think) the time for the first mile run under four minutes, a barrier first broken in the '60s, but I cant remember his name.