Have been on 10 MSC cruises, various ships out of Florida -
1. We only use one device so cannot comment.
2. Easy does not work in Specialty Restaurants but Easy Plus and higher do. If you have Easy just pick up beverages at a bar prior to dining experience.
3. Portions in dining room are more than adequate but if you need more food order more than one entree.
4. We have never had problems with App on board ship.
5. Muster works fine, you do not need to jam up at stairways, wait til crowd clears.
6. I have always booked on line with no problems. Just this week though I booked through an MSC Agent as I wanted two specific cabins and she was excellent.
7. Main theatre - no charge, Back of ships is a theatre that does have a charge - if choosing to go to those shows book ahead, save $.
8. Taking beverages into theatre, we have found depends on ship.