Two.
Dawn's very existence is a big worldbuilding WTF to me. It's never explained. I'm left thinking it really was just a massive clunker committed for the sake of writer convenience and demographics.
This is opportunity for the fic writer but blots on the experience for the television viewer. Truly great fiction doesn't skimp on the world-building. It gets its details right, so they support everything going on in the story. It sure as hell doesn't contradict itself. (Must footnote and say that I can imagine a story having a very good reason to contradict itself, and maybe it would be possible to do that without devolving into metafiction. Maybe.)
Three. Oh,
Four. And