I'm just speculating now, but I think it'd be better if they alter the origin a bit to have him abducted by those aliens as a child (intentionally or otherwise.) The idea that he "joined NASA" is a good explanation as to how he got halfway across the universe seems like a little bit of a stretch.
Personally I think the concept of an orphan fending for himself in a (quite literally) alien environment is a lot more interesting than an astronaut who lucked upon interstellar travel just because he wanted to really badly. Oliver Twist in space if you will. Obviously someone out there would have had to have taken him in for a time, maybe even raised him to an extent.
I don't know much about Star-Lord but what I've read in these links but I like your idea. It would seem to jive well with the attitude seen in the trailer.