Brilliant essay, wondeeful points, and I enjoy how you've brought in all the Whedon-verse quotes (we know RTD was influenced by Whedon et al, and it stands to reason that Moffat plays in that same shared zeitgeist as well).
Thank you. And I am almost physically incapable of writing meta without Whedon verse quotes... (These shows all hit the same buttons. Makes me happy.)

I had a thought -- and I'll have to go back and watch. When River dies in the Library, what happens to her body? Now that we know she is a Time Lady, is there any chance that after the Doctor leaves, she may have regenerated?
Unfortunately not:

DOCTOR: Easy! We beam all the people out of the data core, the computer will reset and stop the countdown. Difficult, Charlotte doesn't have enough memory space left to make the transfer. Easy! I'll hook myself up to the computer and she can borrow my memory space!

RIVER: Difficult! It'll kill you stone dead!

DOCTOR: Yeah, it's easy to criticise.

RIVER: It'll burn out both your hearts and don't think you'll regenerate!

See? Moffat knew what she was even then. (EVERYTHING comes back to the Library episodes. EVERYTHING!)