For the California part of your trip, why are you staying or focusing on Anaheim? Most of the places that you are talking about are in or around Los Angeles, the only thing in Anaheim that you mentioned is Disneyland.
I guess you will probably do it as part of your Rodeo Dr. and BH day but people love seeing and taking pictures of the Hollywood sign. Another nice place in LA is Griffith Observatory, it's way up in the mountains so you get great views if it's clear, it's a really nice place to just hang out and spend the day. Venice beach is pretty fun if you are looking for something "interesting" rather than just natural beauty. I like Manhattan beach myself. Also I like Santa Monica, it's a fun little place, you can walk around and shop on the third street promenade then you can walk to the beach and look over it and the pier.
Also there are nice things to see in the valleys. In the San Gabriel valley you can find all sorts of tasty Taiwanese and Chinese places to eat. You can see Hsi Lai Temple in Hacienda Heights which is a huge Buddhist temple, it's worth a visit in my opinion. Oh also at the California Science Center near USC that now have the Space Shuttle Endeavour which is great to see if you or your parents are into space at all.
Are you driving down to San Diego after your stay in LA? If so I would stop in La Jolla. La Jolla cove is a very pretty place, they also have some pretty nice restaurants that overlook the ocean. It's just a nice area in general.
Also in SD you can go to the USS Midway Museum, I like it because I am into military things, boats and planes, it may not be your cup of tea. If you are going to the zoo I would also consider the Wild Animal Park. It's a part of the zoo but the animals are in a really open environment and you can take a little safari sort of thing through it. That's a bit north from San Diego though.
Oh and if you like restaurants with views (like I mentioned for La Jolla), in Las Vegas there is a pretty nice restaurant near the top of the Palms. It has a ton of windows and you can see out on the strip and entire parts of the city.
I'm jumping around a lot, hopefully it isn't too confusing. That's most of what I could think of offhand that you didn't already have listed. Hope it helps a little bit at least.