First (Third?) Impressions

Like every child of the 1990s, I love Harry Potter. But several things about the books have always bothered me: (1) If Europe's Christians decided to make witches and wizards their bitter enemies for several hundred years, why does the (witchcraft and) wizarding world still celebrate Christmas? (2) Are Muggle-born children really ready to give up their entire culture at age 11 and never look back? (3) Dumbledore's explanation aside, isn't it immoral to not share the "technological" advances of wizards with the rest of the world? It's this last one that irks me the most, though. Not because 100 million people died from the Spanish flu, which a quick spell could have healed, but because every time I travel, I think to myself, "Damn, I really wish I could apparate."