kofferradio

Only shops are closed on Sunday. All tourist spots are open, of course. There is so much to do in Hamburg, but you need to do your research in advance as the city is big and you will need public transportation to reach the spots. Hop on Hopp off is available and might also be an option. - Elbphilharmonie (concert hall with a very nice terrace) - Michel (church) - Landungsbrücken - harbour cruise - Miniatur Wunderland - Hamburg Dungeon - Reeperbahn - city hall - chocoversum - Dialog in the dark - Alter Elbtunnel (small tunnel under the elbe river to the citycenter, can be reached by foot from the terminal) ... Staying on the ship in a city like Hamburg would never be an option for me.

It is possible to book a cabin with a third passenger (e.g. baby) although it's a cabin for two. But you need to request that via your TA or directly with MSC. They have a form for that, I can only give you the link to the german version, but this will be available in other languages, too. Normally the request will be approved (as long as there is lifeboat-capacity). Officially the third person has to sleep in the parent´s bed, but they will will provide a cot in the cabin. https://www.mscbook.com/pages/sdl/img/MSC_CRUISES_UEBERBELEGUNG_41816.pdf

Officially MSC is not offering self-disembarkation on cruises in the Med. It will work most of the times (just go to the exit), but officially you have to stick to your designated number/checkout-time. If this works out and the ship is on time (no guarantee for that, especially in Marseille), you could get the 10:00 train. I would say 20-40%. Only do it if you can rebook the train for free or a small fee. I would enjoy a last breakfast, leave the ship at around 10:45 and take the 12:00 train. Way more relaxing!

Don't rely on a random callcenter-agent. On the German website it is clearly stated, that you don't need any visa if you stay on bord. https://www.msccruises.com/en-gl/assets/reisedokumente-und-visa-rotes-meer.pdf It says, that they are working on a convenient solution for a "transit visa", so guests should wait. Guest who can not wait can alread buy a "e-Visa-Transit-by-Sea" online.