Southern California is fine. I don't think it's right to label it "West Coast", the Bay is part of the west and unless you will allow bay area rap discussion, it's a bit alienating.
I see what you're trying to do, but to label it that won't really help. I don't think the Sicc has ever had a strong Socal presence besides San Diego....maybe something like more LA artist interviews can kickstart things, but a forum name change I don't see doing much.