One other thing that doesn't make sense to me (which I realize that it might have already been discussed several times in some of the 900 posts but, you know ... 900 posts of backtracking... yeah...)
Why is the android willing to test the ooze, an essentially unidentified substance that could be a danger to the entire expedition in any number of ways, on a crew member?
Was there something to suggest that it could have been some kind of eternal life elixir, even though the only thing he knew about it was that it contained some human DNA? What if the effect of the "experiment turned out negative (horrible, backfiring effects that would put Weiland's and the rest of the crew's lives in jeopardy not withstanding) - what would he move on to next? Looking for another random piece of alien technology to infect the next canon-fodder crew member with?
And why was Weyland so impatient for results? He couldn't wait a few more days of proper exploration and research from, you know, the explorers and researches that he payed a trillion "credits" to round up for the mission, considering all the top of the line research hardware that they had on the ship, when he already spent 4 years in hyper sleep? Because, at that point, they had no reason to believe they were in any danger, and didn't need to rush things.
Or, maybe Weyland didn't mean anything that extreme when he told the android to "try harder", but the android suffered a short circuit in his robot brain and could no longer make use of any of his basic common sense faculties - which would explain why he thought that all children want to kill their parents because Vickers had feelings of animosity toward her father... So much for his billions of zeta-flops of computing power.
And what was he going to do when the crew found out that they were being experimented on by the ship's synthetic? Was he planning to kill everyone and conduct the research on his own? What was his backup plan for when he would run out of guinnea pigs? (Although, considering the crew's inexplicable willingness to instantly move on from and forget horrible acts done to them by their ship mates, that might not have been as big an issue as one would expect...)