I have to concur. They're using the concept of moral rebirth as a sort of origin story for the modern version of Thor.
It's an intelligent experiment in storytelling, but I just don't think it's going to work for what's essentially a kids' movie.
If they wanted to do a normal origin story, they should have just gone with him being a god in Asgard the whole time, glorified for his battle prowess and the toast of the town. As I understand it, they have this thing called Valhalla that glorifies war and dying in battle.
Make Thor kind of a dick. His victories have gone to his head and he's pissing everyone off, but they can't argue with his success. Plus, he's a product of his society. Maybe the ultimate product of a society that values battle glory.
Then have Loki serve as the cautionary tale. Loki does something fucked up that forces Thor to make a terrible mistake due to hubris and all of Asgard is imperiled. In order to save Asgard, he must make an uncharacteristic sacrifice that strengthens him as a person. The downside is that at the END of the movie, Mjolnir ends up in the desert and nobody knows where Thor is except for Odin, who oversteps his bounds and allows Thor to be reborn in the body of Don Blake. When the time is right, if Thor's learned the lessons he needed to, he will one day again be Thor.
This allows Loki to be the villain of the Avengers movie, who learns somehow about Thor's mortal life and seeks to keep him there forever. This serves as the catalyst that will bring the Avengers together. It makes sense since he was the first villain they ever faced as a team, and it introduces all the other super heroes to the idea that metahumans aren't just products of science, and sets them up to face threats terrestrial, cosmic and interdimensional.
Marvel should just hire me to be in charge of their movies.
