The California coastals are very nice.
I definitely agree that the San Diego Zoo is world class. It is well worth a visit.
Ensenada is a port they touch to comply with the Passenger Service Act. The tour that visits the blowhole and then goes to a folkloric show is worth while, if not stupendous.
There are soooo many things to do in San Francisco. The Alcatraz tour is fun. You can also walk (if you are in good condition) or grab a cab to Pier 39 on your own, walk around and enjoy the attractions including the marvelous aquarium and simply take the Alcatraz tour on your own. it is easy to book right at pier 39. Another worthwhile thing is the tour to Muir Woods. The redwoods are spectacular.
Santa Barbara is mission and wine country. We arranged a private tour there with a company that specializes in wineries.
A pre or post cruise tour of LA would be a great idea. There are again soooo many things to see. We booked a van and created our own itinerary for a 5 hour tour pre cruise and it worked well. You can see that tour and others from our CA Coastal at
I know you are going to have a GREAT cruise!