4. Colin R: I didn't really have a single point here. Yes, I do feel that the films and the books need to be considered separately. But as someone invested in the source material, I still have opinions about what was done vs. what could have been done. I can't justify everything Jackson decided. Some I flat-out disagree with, but most I can at least understand. One of my major points, though, is that the existing source material wasn't actually stretched into three movies. If Jackson really covered the source material (The Hobbit) and intended to fill in all the gaps as they exist in the book—where did Gandalf go, what's the significance of the Necromancer, what's the deal with the Elvenking, where was Thorin all this time before the quest, how did Gandalf get the key to the Lonely Mountain? etc.—then this could have been five films or more, easy.
You are absolutely right about the dwaves vs. Smaug. It accomplished nothing in the story except maybe gave us a little glimpse of Thorin's personal enmity with Smaug. Which is neat but not worth all the chasing and gold-melting.
I will say, I'm not particularly pleased with the lazy Strider hook at the end. In Fellowship, it's established that Legolas was sent to Rivendell as a messenger that Gollum, who Gandalf had left in their keeping, had escaped. He wasn't just wandering the world with Aragorn, as Jackson suggested it. But whatever. Again, it paints a picture of a slightly different Middle-earth.