My theory about becoming a Slayer and the spell in “Chosen”

As everybody else after “Chosen” I was thinking about the spell that activated the Slayers, its possible consequences, and how it will work in the long term. Slowly a theory emerged. It is quite possibly wrong, and I am not sure if it works on all levels, but it works for me on mystical and metaphorical levels. I was trying to tidy it up and make it all clear and comprehensible, but since it took me too long time without much positive result, I decided to post it here for a test drive, and hope for some reasonable suggestions.

( Becoming a Slayer. Spoilers for the BtVS 7.22 and AtS 5.11 )