Flying into Shanghai for 2days, then cruising to 4 Chinese ports before ending in Japan.

U.S. citizen flying into SHfrom Tokyo. Staying 2 days in SH, the boarding a cruise that stops at 4 chinese ports before going to South Korea and Japan. Returning to the U.S. from Japan.
1. Do I qualify for the 144hour visa free transit?
2. Do I have to do anything to get off the ship at the other 4 Chinese ports?