You're correct, everyone who is a death eater calls Voldemort, the Dark Lord, only Harry and Dumbledore call him by name, Voldemort, everyone else has been He Who Must Not be Named.
As for Snape being chummy with Draco and whether or not Snape is still a death eater or loyal to Dumbledore. I believe he is loyal, and remains loyal to Dumbledore. To remain on the good side of the Malfoys, and Draco, would make sense. Since Snape is the head of Slytherin, keep your enemies close.
GoF is my favorite book of the series so far, not the movie (although the dragons were really well done). Like T and iSm, Prisoner of Azkeban is, thus far, the best film.
Hmmmm, maybe I will put them on my iPod for the drive across country.......
