Creator Backlash: Presley grew to hate the movies he was starring in (several sources such as the documentary This is Elvis suggest he even got physically ill from them at one point), and certainly you can scour Elvis' live performances from 1969 to 1977 and except for one or two exceptions that became regular parts of his act you'll find very few performances of movie songs from the post-1960 era.
What Could Have Been: Elvis never toured outside of the US, mainly because his manager, Colonel Tom Parker (real name: Andreas van Kuijk) was an illegal immigrant from the Netherlands and couldn't get a passport.
More like a case of Critical Research Failure on Parker's part: he had served in the US Army and was married to an American citizen. Parker could have applied for legal citizenship at any time based on either of those two factors. Maintaining his Dutch citizenship, however, did prove advantageous to him in avoiding legal trouble.
According to Parker's biographer, it's possible that he fled The Netherlands because of a Dark and Troubled Past and was fearful of having his true identity revealed.
Barbra Streisand wanted Elvis to star with her in her remake of A Star Is Born but Col. Parker nixed it, insisting Elvis get top billing and a huge amount of money. Kris Kristofferson got the role instead.
When Sam Phillips decided to sell Elvis's contract in 1955, Atlantic Records entered into the bidding for him. Atlantic bid $30,000, but was outbid by RCA Victor who paid $40,000. Atlantic vice president Jerry Wexler loved Elvis's singing and bid aggressively, although he later admitted he didn't know how Atlantic could have raised the $30,000 if their offer had been accepted.