I always have a headlight and a taillight on my all my bikes. It's like a helmet, just because I am riding during the doesn't mean that I won't find myself out after dark. Just yesterday, I decided to go out for drinks after work with some coworkers and I was out way after dark. My entire commute is on the street, no mup, no sidewalk, and no bike lane so lights are a necessity after dark.

I would also look into trying to fit fenders on your commuter, I realize that So.Cal isn't known for heavy rainfall, but every time you ride through a puddle even some damp dirt, it will attach itself to your back. That rack might to a good job of cutting down on that spray, but I really can't stand riding a bike without fenders anymore these days.