I'm a geek of all sorts - science and linguistics.
Ok, the Malfoys. Mal in French is bad. Foi is conviction, faith. So, Malfoy would be bad faith. Draco can be compared to Dragon, the mother, Narcissa, from the Greek legend Narcissus: the best-known version of his legend is as follows. Narcissus, an extremely handsome young man, rejected the love of every girl, who fell in love with him, and they asked gods for vengeance. Once Narcissus bent over a stream to take a drink and saw his own face. He fell in love and indifferent to the world he stayed watching and talking with his own reflection until he died. Lucius is awful close to Lucifer.
Oh, and Lupin comes from the Latin Lupe, wolf. Also the name Argus (as in Filch) comes from the Greek Argos, who was a monstrous creature whose body was covered in eyes. Nicholas Flamel was a 14th century French alchemist and calligrapher.
She uses Latin a lot in spells of course, and the creatures she uses are usually right out of local folklore, myths and legends. Kappas, for example, are water demons from Japanese Shintoism who pull children under the water and drown them (ugh). And to go with Diagon Alley, there is Knockturn Alley = nocturnally.
BTW - I really enjoyed the 5th book. I read it straight through to find out how it ended, now I'm reading again for the details.
*edited to add: oops, my bad. Guy Fawkes tried to blow up Parliament, not the Tower. I always mess that up - I just had to confirm.
"Is ice hockey hard? I don't know, you tell me. We need to have the strength and power of a football player, the stamina of a marathon runner and the concentration of a brain surgeon. But, we need to put all this together while moving at high speeds on a cold and slippery surface while 5 other guys use clubs to try and kill us. Oh, yeah, did I mention that this whole time we're standing on blades 1/8 of an inch thick. Is ice hockey hard? I don't know, you tell me. Next question."