Question: What did Daniel's wife die of?
Question: What is the time frame after Sam's visit to the airport to see Joanna off, and the last scene, when the prime minister returns?
Answer: Approximately 1 month later.
Question: Is the mother or daughter who sing "All I Want for Christmas" at the Christmas pageant an actual singer? The way the teacher introduced the mother who helped put the number together, he made it sound as though she was a well-known musician, so I wondered if that was true.
Answer: Ruby Turner, playing Mrs Anderson is an accomplished singer. She started with Culture Club in the mid-80s and then went solo. Olivia Olson, playing Joanna, is also a singer. She won on Star Search and as far as I know has only released two songs. As for whether the Mom is supposed to be a real singer in the film, it's not made clear.
Answer: The staffer introducing the concert says "and background vocals coordinated by the great Mrs. Jean Anderson." While not explicitly stated in the film, and he could potentially mean that she is well-known in another field, or that she just did a great job with the concert, it certainly sounded to me that the character of Joanna's mom is intended to be a well-known singer.
Question: Even if Karl and Sarah don't get together at the end, I couldn't see what exactly was stopping them?
Answer: It's because of the complications that Sarah was having with her troubled brother. Apart from that, who's to say they don't eventually get together?
In the follow-up short film (the Red Nose Day special) we learn she eventually gets her happy ending with a man played by Patrick Dempsey.
Answer: The end of the movie is not the end of the story.
Question: Whatever happens to Karl and Sarah? Are they the only ones who don't get together at the end?
Answer: In the follow-up short released last year it's revealed that, while she never got together with Karl, she ended up having a very happy life with a great husband (played by Patrick Dempsey) and children.
Answer: Karl and Sarah never get together, he just has that scene where he says Merry Christmas, and leaves.
Answer: Sarah's brother's therapist tells her the constant contact is preventing his progress and she needs to give him more space. She and Karl then get together.
That never happens in any way, shape, or form in the film.
Question: Why is Daniel so supportive of his son being "in love"? It's not entirely unheard of for future couples to meet during childhood, but Daniel actually refers to the girl as the love of his son's life; something that would be dubious to most parents when their child is not even a teenager.
Answer: He's simply going along with what his stepson thinks. He knows, as most parents do, that arguing with their children about whether they're "really" in love is pointless.
Answer: Daniel is so supportive of his stepson because he obviously loves him deeply, despite his own pain at just losing his wife, he understands his stepson is not only dealing with the extremely painful experience of losing his mother and also dealing with the pain of his first real crush. Daniel is a great Dad.
Answer: It's never really specified, but most likely from a long illness. There was no reference to it being unexpected or a tragic accident.