Psychobabble! Its like you want us to not listen to you! Pseudoscience notwithstanding (is that one word?), I fail to see your point's relevance to a snuff or no snuff debate.
In my opinion, character death is a powerful plot device that is immensely capable of being the main plot on its own. That said if the premise of the story is character death and the rest of the facets of good story-telling are ignored or overlooked its just PWP fluff. I also think if a character the author likes dies, the effects seen in the writing amongst the other characters will tend to be realistic than they would be in a "Fuck! I hate Rinoa! Lets have Angelo become rabid and tear out her throat so I can have a good giggle" fic. (Someone should write that.)
I would never pick a character I dislike to be the one snuffed, I'd pick a character that'd have a startling impact on those that survive him/her. Because, that'd be the better story.