I live on the Central Coast. Perhaps this comes from bias, since I was born and raised out here, but I grew up with the understanding the Central Coast is the dividing line between Northern and Southern California. In my opinion, anything north of SLO county (Valley doesn't count, though one could maybe say anything south of Bakersfield is Southern Cali) is Northern Cali, and SLO County included going south is Southern California.
To give some perspective, when I was a kid, my parent's would sometimes drive us down to LA to Disneyland, Knott's Berry Farm, etc. Sometimes, when we'd go, my parents were able to get a "southern california" discount, with our county being the furthest north on the coast to qualify.
I love Manderson's skating, and have faint memory of enjoying some of his interviews. With that said, remember that all these guys are human beings. They have their faults, and putting them up on a petestal and thinking, "Oh this guy doesn't fuck with that dude, that dude must be the worst!" really discredits what the actual case is. Theres a lot more nuance to life than that.