I don't really know the comics, so, I can't comment on the "Canonicity" of Hal and his fears, or the portrayal of Hal or of Carol, but, I will say it all worked for me.
Yeah same here. There were a couple times when Hal's fear was a bit oversold, but frankly I STILL found it a lot less cheesy and ham-handed than all that "responsibility" talk in the Spidey movies.
And hell, it makes a lot more sense that someone WOULD feel scared and completely overwhelmed after going through what Hal goes through in this movie. No matter how much of a cocky badass they make themselves out to be.