Clark travelling the world is canon. In many iterations, he didn't go right from Smallville to Metropolis, but travelled the world in order to find his place. It's not brooding. It's soul searching.
As far as the big war and such, that again is canon, which also ties in with the idea of the S being more than just an S or representing the House of El. Superman Birthright had the S represent all of Krypton; a unifying symbol after considerable civil unrest.
Seems to me this movie's story, or at least parts of it, borrow from Birthright. Given how much I liked that story and its reinterpretations of the mythos, I'm totally okay with that.