Howard Hill, one of the great archery experts of the 1930s and 40s, worked on the earlier Errol Flynn classic "The Adventures of Robin Hood" and in particular, provided all of the special trick shots during the famous archery tournament. He taught Flynn how to use a bow and arrow and presumably did the same for Cornel Wilde on this film.
The composer of the score, Hugo Friedhofer, worked on the earlier Errol Flynn classic "The Adventures of Robin Hood" as chief orchestrator for Erich Wolfgang Korngold's award winning score. Certain elements from that score can be heard in Friedhofer's work.
The Regent withdraws the Magna Carta and, when the nobles agree, the Earl of Huntington (the former Robin Hood) vows to fight him and maintain the people's right to rule themselves. In fact, the Magna Carta didn't create a democracy, it was forced upon King John by the nobles to guarantee the rights and establish the political power of the nobles, not the people. The nobles would never have let the Regent withdraw the Magna Carta and strip them of their power.