The goat-gland trebuchet thing inevitably brought up mental images of that great work of comic art (that must certainly be part of the archive aboard the ark:
(I hope this pic works) One might differ about the suitability of different ruminants as missiles.
I saw the Japanese animation, which was very nicely done, but the meteor depicted in that film is 10 or 20 times bigger than the one I had in mind. In that scenario there is no survival possible (unless we can start colonies on other planets).
Sugar has a very high energy to weight ratio and is therefore good to keep as emergency ration, apart from it serving as food for numerous insects as mentioned by Farmerman. Excess sugar can be turned into alcohol for fuel.
In the case of the ark scenario, the crew will for a large part be selected on their suitability for the trip. I think it will be inevitable that some of the crew are religious, but I would never choose some fanatic. I guess they would not want to come along either, since they probably will be trekking to a mountain top to happily await Armageddon (or use the breakdown of law and order to start bashing the brains out of infidels).
I do consider it quite likely that some people will turn to religion in the face of the hardships of survival (in times of war and catastrophe the churches are full). But aboard the ship we will not encourage religious fomenting and uphold the Western lay law that religion is personal and none of the public services (like education) will support any particular faith.
For the duration of the voyage and the early parts of the building of the colony, I would expect that the battle against the odds of chaos and barbary will be the uniting force that will hold the people together, but perhaps once a certain level of security and opulence has been reached, religious factionism could rear its head. On the whole however, I expect within the limits of the story to deal only with individual elements that might frustrate the survival effort (as in "one man's evil becomes the curse of all").