Edward and Bruce
After spending quite a while researching Robert the Bruce, his younger brother Edward Bruce, and other related historical figures, I hit upon the idea of considering
Edward Nygma and Bruce Wayne, also known as the Riddler and Batman, a pair of famous fictional foes.
Turning my back on you
A la a dramatic insult
Like Edward and Bruce
The spoilertagged hint tells us that we should be looking for a historical character A who's somehow related to puzzle history. When I noticed the italicisation of the words "Turning" and "A la", I realised that these words together form an anagram of Alan Turing. He worked on cracking the Enigma code, which links to the E character via " E Nygma". I'm not sure if there's any riddlish meaning in the first two lines, or if they're just meant for wordplay.
QUWZTF
Z'QAQ
UXTRO
SXURM
YYYQZ
MMMD'
As Techidiot discovered, this is a Caesar-shifted cipher intended to be read vertically. Shifting each letter backwards by 10 places gives:
E I K N H T
N ' E O E
I L H F C
G L I F A
M M M E N
A A A R '
and hence the message "ENIGMA" (confirmation) "I'LL MAKE HIM AN OFFER HE CAN'T".
Clearly, the word to finish off
this famous (mis)quote is REFUSE. The quote itself is from Vito Corleone (the fictional character V), played in the film The Godfather by Marlon Brando (the historical character M).
I spoke for him
But I am not big and furry
Where was I born?
Searching Google for "spoke for Marlon Brando" led me to Sacheen Littlefeather, who "gave a speech at the 45th Academy Awards ceremony on March 27, 1973, for actor Marlon Brando, who was declining the Academy Award for Best Actor which he had won for his performance in The Godfather". She is indeed not big and furry - her name is instead "little" and "feather"ed. And the fact that Brando declined the Academy Award links back to the missing word REFUSE from the previous part of the puzzle.
So the final answer is
Salinas, California, the birthplace of this actress.
Feedback section
Hints 2 and 3 are, as hints should be, not really necessary. But without Hint 1, this puzzle would be more or less unsolvable. Three short lines of poetry in the 1st part, of which only four words are actually used, aren't really enough to find the required word, nor is the unfinished quote in the 2nd part enough to discover the correct people for the 3rd part, without knowing the information in Hint 1.
Also, the different parts of the puzzle don't fit together as well as they could. Ideally, the 1st part would give a solution which would then be used to decipher the 2nd part, whose solution would then slot into the 3rd part. Instead we have the 1st and 2nd part solvable independently, the 1st part and a chunk of the 2nd giving a solution which is then never used again, and only the rest of the 2nd part giving the solution which is then used in the 3rd part. It feels ... disjointed, with too many red herrings.