I think your analysis is spot-on, but the episode was lackluster. Most scenes were overwrought and mawkish.

I think this Ellen as the 'Last Cylon' is a red herring; that's not to say that she isn't a cylon, but rather, I think that everyone is both cylon and human. The cylons need to discover their mortality, the humans their immortality. 'The cylons nuked the planet so they could discover the preciousness of life' type of thing.

TV is doing it for me less and less these days, so if I can actually make it through the entire season to see how it pans out, I'll be impressed.