good observations. You really put some time into getting down to the nitty-gritty in these cells however I'm going to answer a couple of your points.
First of all I agree with you that Eddie Kane is a complete psychotic idiot. As far as being one of the darkest of the whole series, I suppose he is up there. The word creep is appropriately used to describe him.
Secondly, the use of the word Valley is referring to the San Fernando Valley which is an area about 20 miles north of Los Angeles that always takes the rap in real life and in movies. I used to live there. There's too much traffic, too many people, too much smog, too much industry and it's hotter than blazes in the summer. So that's why it gets a bad rap.
Yes, you can say “he was killed by a bomb”, “he was killed in a car accident”, “he was killed when he slipped and fell”, etc. “He was murdered” is used only when killed by someone else.