It does seem like a really formidable job. I probably won't get started on this for awhile, but it's definitely on my "hope to do" list.

Definitely episodes like Hush won't be included, but Hush is also the episode when Tara and Willow first combine their powers, which is definitely a crucial moment in Season 4 -- and that's just one example of what I mean by not being able to isolate plot elements like that. Maybe I will find a way to do it, maybe I won't. It may turn out to be simply impossible, but I refuse to believe that...