The good thing about Dancing Lawn is normally if a thread starts getting heated a mod and/or other members will step in to gently correct or redirect behavior. Most of the time, reminders of polite behavior are really all it takes to get most members back on their best behavior. I think most of us here want this to remain a respectful place, so people accept any warnings they get and tend to modify their behavior.
Yeah, I think you chose good topics to spark dicussion. People are familiar with things like Harry Potter and everyone probably has got an opinion on the series.
Facebook has some nice things, but some of the people you have to deal with on it are crazy. When I see some of the things my "friends" (more like casual acquintances) post there, I'm like, "EEK. Don't feel the same way about that at all." So Dancing Lawn is a nice haven for me online since people normally are kind, respectful, and have strong values.