Diclaimer: this is what I was told. It may not be true but is certainly confusing.
Yes, I believe so. They are two separate, diffent things. I am not sure if you can see linked dinner reservations. You have to call to link dining. I think others may have to call to accept the link.
The link for shows, excursions,etc is accomplished via app or web site. Use the add a cruise. You need res #, last name, DOB. Not sure if they have to accept. I do not think so because you have a lot of their info. After a bit you can check it by seeing if they show up in your cruises.