Despite the righteous close, Pax allowed me to post:
I wanted to add this to the fray:
If one is interested in an excellent exposition of the rationales for killing in SD in modern juris prudence and the historical background - I recommend:
http://ukcatalogue.oup.com/product/9780199283460.do
Killing in Self Defense by Leverick. Mentions many of the issues here and references the RKBA world literature.
A dense but good read. It discusses the right to life as compared to SD, property, retreat, rape, killing vs. stopping, etc.
Glenn