1) It's privately funded, and rushed because Weyland's almost dead.
2) Wow, a guy modified his suit. Call the movie police, we're dealing with insane levels of improbability here!
3) The most important mission privately funded by a man wanting not to make any further significant contributions to science, but who wants to grant a dying wish. A man who finds that all his vast wealth leaves him unfulfilled, and who is willing to sacrifice others to meet his maker and prolong his life. So while others may think that the mission is the most important in human history, it was all organized, financed and orchestrated behind the scenes by a man with a different mindset.