Prometheus: Huh? What?

I saw Prometheus on Friday. It had some very nice visuals. It had some very nice action. However, the more I think about the plot, the less sense it makes. My current best explanation for the events of the movie requires every major character to be unprofessional, mildly retarded, a sociopath, or some combination of the three. So confused...

For more details, see Howard Tayler's review (warning: comments section is full of spoilers). His opinion is a bit more charitable than mine, but it's in the same vein.