Yes seen that before, found it a bit smug and pedantic to be honest, but then it is the Guardian so I suppose I should expect that!
1. They answered their own question
2. They answered their own question
3. Explained in the film - money
4. Fair question, tho they can't ask why it affects Engineers, humans or snakes in different ways because they are different to start with!
5. Cut scenes, viral videos, to play a role in a sequel
6. It's not that he doesn't want to reveal himself, but he only has "days" to live, so is kept in hypersleep until necessary to get up
7. Holloway gave David permission to put the goo in his drink, in a roundabout way!
8. She pumped herself with pain killers quite regularly after the op and was obviously in a lot of pain (altho this did seem to disappear when she was running away from the crashing ship). But hey, this is the future and an advanced-by-the-future's-standards surgical machine did the surgery!
9. That the very question is asked is probably praise for the film as this is the kind of question sci-fi films should leave us asking ourselves. Saying that, it's more likely to whet our appetite for a sequel (read trilogy)
10. Think plenty others came up with the story before the X-Files did!