I'm curious- what stuff did you think was unnecessary? Everyone they showed played a role important to the story- from Brainy going with Sara to get back baby Jon, to Dreamer and Kelly helping with the evacuation, to Lena and Alex science-ing it up to get the people to another dimension. I guess the only part of them that dragged was when Alex recruited Lena, and Lena's repeated "This doesn't change anything", but her calling out Alex about the Claymore Satellite was kind of needed, since Alex did come close to killing her last episode.