when in season 1 it was always Don interacting with Charlie.
That is so true. But it's probably because everything is new for both of them. Now Charlie walks into his office with all his confidence why in the first season he was still a bit shy. One of my favourite scenes in the first season is when Don find's out that Charlie has the highest security clearance. :D

I miss Megan in the first season too. I never liked Terry either, but Megan from the very first moment. I think they mentioned something why Terry went away.

I never got far with the quotes, it's really difficult for me to get every word.