I was in San Fran earlier this year 4 day stay. Alcatraz trip approx 33 dollars book online b4 you go. Print out ticket. Need to be at pier half hour b4 your timed ticket, as they willfill the ferry with untimed ticket holders b4 it leaves.
You can leave Alcatraz at any time, the tour has headphones and you can go at your own pace. To avoid climb on arrival and get good photos I'd say take the train style transport on offer both ways. The tour guide gives you information and it can offer priority on boarding the ferry back!
Re Sausalito, remember to sing Sitting on the Dock of the Bay, that's where it was written.!