1) He was seeding a planet with life using the black goo.
2) No payoff, really.
Except, perhaps, the actions of the individuals in that film helped influence David's actions.
3) I have no idea. Was he too concerned with what the main group was seeing and with watching the progress of the storm? Did he think 'They got this', and when they didn't call for help because they didn't know they were lost he didn't give them any?
4) I think he had been watching them through the cams for hours, and nothing at all happened, no danger either on the map or through their headset, so he thought they were going to be fine in a place that, given all evidence, was abandoned.
5) A medpod under the control of the woman threatening him with a flamethrower.
6) Bit iffy there.
7) I think everyone knew. The indication I got when Ford and the faceless mercenary guy came to get her in biohazard suits was that David had told them about the impregnation of the alien. Thus, given that nobody else on the ship was qualified to do surgery (David says this), the precise gash and staples on her stomach would indicate exactly what had happened to those seeing and helping her afterwards. As for why no one went to check on it, no idea. But I imagine Shaw thought it was dead, or at least adequately contained in a medpod that was in an easily ejectable room in the ship, thus explaining why she didn't mention it. But I still think this could have been fixed with three or four lines of dialogue.
8. No qualms with that point.
9) Agreed.
10) I am inclined to agree with the latter.
