I'd just like to add (to your incredibly insightful post :) that I have found cannabis to be a hinderance/toxin for my immune system...it seems whenever I've smoked, I virutally always end up taking a round of Vitamin C and/or Echinacea, just to ward off that scratchy, uncomfortable, "ooh, I just KNOW I'm coming down with something" feeling.
I worked at a Hospice for a few years, and the usuage of cannabis to increase appetite and prevent nausea was undisputed amongst the patients and nursing staff.
And for me, the increase in creativity is phenomenal. But it doesn't seem right to have to "take anything" to be able to find the creativity that is obviously already locked inside me. I wonder how I can "unlock the door" without chemical assistance.