We did this same trip Feb 2017 starting in Saigon and ending in Hanoi. We came in a couple days earlier so did some touring on our own first. Seems like AMA is doing more touring this year in Saigon than 2 years ago. We did the Chu Chi tunnels on our own as this was not available through AMA. We went to a market on our own.
They had a table set up at the hotel (near lobby) so you could pick up your itinerary package and then there was a meeting later to meet everyone and go over the agenda.
The hotel was very nice and I do remember walking about a bit. Traffic in Vietnam is something else and crossing a road is exhilarating (if you like taking chances!).. lol
This was the 2nd cruise we had taken with AMA, the first in Myanmar. They certainly have these trips down pat..
Sorry can't answer too many of your questions but hope you enjoy your trip.
We've enjoyed these river cruises in SE Asia so much we are booked on a 2 week river cruise on the Ganges India in Oct.