Also, it would seem that the word "rake" has some colloquial meaning that I've never heard before. From context I assume it's something like "willfully evil person", but I don't actually know.

It's an early modern-era term for a man accustomed to vice, especially sexual misconduct. I particularly associate the word with "A Rake's Progress", a series of paintings depicting a young aristocrat's descent into debt and insanity by way of all the dissolution you'd probably expect to find in a story like that, but you needn't limit it to that.