Overanalyzing? No, just analyzing. Dramatic choices are a story -- but stories are very telling.

My issue is that claims of BSG showing a post-racist, post-sexist society are undercut by persistent artifacts from the writers' own society.

It's not that I cannot love! or something; racist elements in Tolkien (ferex) don't prevent me from very much enjoying The Lord of the Rings. BSG just made claims about its society that the writers have (probably unintentionally) subverted by the dramatic choices that were made--choices which were not accidental, nor necessary, but are significant.