We originally chose this cruise because it was cheaper than Carnival, we wanted a 7 day cruise and didn't want to fly (we live in Arizona.)
We took time in LA beforehand to explore the Jewish Holocaust Museum (we should have spent hours there), took a Warner Bros. tour (made for "Friends" and "Ellen" fans, though the Batman and Harry Potter parts were good), the Los Angeles Mormon Temple (amazingly peaceful grounds) and sampled some Indian food. It was a great day. Next time we will spend more time at the Museum as well as doing other things. Driving in LA is still crazy on Saturdays.
Embarkation was smooth, but slower than other cruise lines. Disembarkation was not nearly as pleasant and took twice as long. They really need to figure this out. It was the longest and most confusing process of all our cruises. If I had to do it again, I would either be in line at 6:30AM or I would eat a leisurely breakfast and saunter off at 10AM.
See above.
LA is very interesting, with lots to see, but traffic wastes a lot of time.