Don't change clothes... just don't spill on yourself when cooking. No, freezer bags are NOT good enough. Get a good bear cannister; REI rents them for cheap. There are also soft-sided bear containers. We usually had a bear cannister, but would bear-bag the majority of our stuff. Never had a problem with either.

Correct, no deoderant in the car. If you bring it with you, toss it in the cannister or bear-bag at night. But, you might smell yummy if you use it, so personally, I wouldn't.

No food in the car. Period. Unless you like a broken-into car. Many places have bear cannisters at the parking lot; look into it.

When hiking, it's food. Keep it with your bag. You can snack. Eat, drink, and be merry. No, the bear won't stalk you trying to get your power bars.

It's the wilderness. There's bears. And bugs, fish, other hikers, marmots, mountain lions, coyotes, squirrels, etc. Providing bear boxes is a courtesy. They probably got tired of people complaining about bears eating campers' food because they didn't take proper precautions.

I've never tried the pee bottle - it's never been a "wise idea" IMHO, simply cuz I have no hand...er... pee... coordination at night. I might stumble 10 yards from my tent. Just don't pee on your friends tent. I don't think bears are like dogs where they have to run over, smell it, then pee on it too.

Everything OBG has said is right on. You'll be dealing with black bears, which are basically big wusses. yell, make noise, toss rocks if you see them. They tend to run off. The only grizzly left in CA is on the state flag. Don't pick up the cubs. Worry more about the hordes of mosquitoes than the bears. Buy some after-bite.