Yes, yes, yes, on all points. It's your dragon, so motivation for his actions are all yours :P I also agree that the setting should be somewhere not earth, perhaps a place with two moons, I've always found the pretty. Perhaps we could go with something like they simply are having a harder and harder time making connections with others of their kind because their very nature is shifting into something that makes getting close an issue. This would go along with your idea of the dragon going to humans out of loneliness. Human, despite all the infighting we tend to have, have never had a problem getting close to one another :P

As for do humans know about them. . . . .How about on the cusp. Like, they believe in their existence, but it's just been so long that people are starting to believe they've all died out or moved somewhere else or something. Your thoughts?