The scene in the village pub, in the flashback to the time of the Riddle murders, deals with a recurring theme in the series, the way groups of people can easily be misled or even fool themselves into believing things, when they should really employ more critical thinking. Often this happens because of the Daily Prophet, but in this case it's just a group of Muggles gossiping and ending up with the conclusion Frank must've been guilty, for no good reason at all. Add to that the thoughtless cruelty of the village youths in vandalizing the manor, and you're left with a not particularly pretty picture of our society.

In the third chapter, the brief mention of Percy's new job and the admonition to not mention anything about foreign countries somewhat reminded me - our resident Brits may disagree - of British euroscepticism and the idea that Britain should stand alone and not let itself get tied up too much in the affairs of the continent (although of course Percy's job is not limited to Europe, as we'll see in a later chapter with the great discussion about the import of flying carpets). Muggle Britain is quite strongly involved with the continent and with other countries, obviously, but magical Britain not so much - it seems to be rather more isolationistic. This and other things further in the book, such as the schools issue, underline Rowling's failure to make the international magical world credible, but okay, you can't do everything, and it wouldn't have been particularly useful or interesting to flesh these things out properly.