In praise of The Prisoner but with questions

I love The Prisoner of Azkaban. The more often I read the Harry Potter novels, the more I come to recognise how clearly this novel rises above the others in my estimation.

I think J.K. has been quoted as saying that it was the easiest of the books for her to write and I think that shows too, in the quality of the narrative, in the smooth flow of the writing, in the intensity of the experience for the reader. It reads like a spectacular roller coaster ride, a smooth but terrifying journey.

I'm about a fifth of the way through Azkaban again and, as usual, enjoying it very much. I enjoy our first meeting with Stan Shunpike as much on this, my 20th or so reading, as I did on my first reading. I am impressed with the way Rowling, truly one of the most clever writers I've ever read, is able to focus the attention of the story on Ron's rat, Scabbers, in the early part of the book without giving the reader the slightest inkling that the rat is, truly, the central character in the novel.

Rowling simply inserts Scabbers (and his conflict with Hermione's new cat, Crookshanks) as a constantly arising point of conflict between Ron and Hermione and allows her reader to focus on the conflict without recognising that she is putting Scabbers squarely into our field of vision on a regular basis.

I have a couple of questions, though, on issues which I think might be engendered by the speed with which Rowling wrote this book:

1. Why does no one mention, either to Harry or otherwise, that Sirius Black was a member of the Order of the Phoenix in this novel? Shunpike, for example, states in a matter-of-fact way that Black was one of Voldemort's key supporters. Was he? We learn later that he was a member of the Order, the group actually fighting Voldemort. Could his apparent betrayal of James and Lily and his purported murder of 13 people be sufficient to make everyone forget his role with the Order? I would think they would be talking more about his betrayal, in the end, rather than his place with Voldemort.

2. Why does Lupin have "Professor R. J. Lupin"  stamped "in peeling letters" on his case at the start of the book? He wasn't a professor before this year and he doesn't continue to teach afterwards. We get no indication throughout the rest of the novels that he is a trained educator: his position teaching Defense Against the Dark Arts in Harry's third year appears to be a "one of" for him, welcomed employment thanks to Dumbledore. So why would he own a battered old case with "Professor R. J. Lupin" stamped on it in peeling letters?

3. Why do the Weasley's choose to take a holiday in Egypt as their "special treat" with the winnings from the Daily Prophet Grand Prize Galleon Draw? Mr. and Mrs. Weasley had gone to Egypt just the previous Christmas, a trip that their children were apparently welcome to enjoy with them but had chosen not to do so (see The Chamber of Secrets). Wouldn't they have chosen some other place for their celebratory holiday, a place they hadn't just visited?

4. What happens to Crookshanks in the rest of the books? He plays such a big role here and certainly Sirius says later in the book that Crookshanks is "the most intelligent of his kind I've ever met". Yet he doesn't really do much for the rest of the series of novels. Why not?

Picky points, I know. As readers of this blog know, I just love to find these little questions, to point out these minor issues in Rowling's incredible books. I hope I'm not offending any one; I just find it fun to do.