I still evaluate all that we have seen- the ex's, the relationships shifting, Chuck's development as a spy, without the physical prowess -- as essential. Chuck, if he does become a full blown spy, would have to walk away from his family, and the re-connection, the re-introduction of each character from his past- they lead to and develop the arch here of an evolving character.
The drop in of lines that have such a powerful impact are the best, and the writers are delightful. Less humor? I don't think so. The humor line is being carried by the Buy More crew when Chuck gives it up, or by Casey-- and Adam can deliver a throw-away gut buster like no one I've ever seen.
I could happily see much much more!!!