I loved that we got some background to Sue. It showed that she's not completely mean and heartless.
I agree, I would have liked to see some reaction to Puck/Rachel being together. Nobody seemed to notice even though it should have come out of the blue for all of the characters because it went from Puck paying no attention to her to them being together. It showed a nicer side of Puck. I think Rachel brings out a better side of him than anyone else.
I don't like Finn either. He's used so much but I don't see why. They seem to use him as one of the musical leads when I don't think Cory's voice is that strong. Hopefully, Finn will come along a bit more and I will start to like him more.