Yes, if you go into the experience having an idea what to expect and are not looking for an HAL cruise you may be pleasantly surprised, but from you remarks, especially the first posting it does sound like you don't expect it to be a good experience. You are looking for those of us who are loyal to NCL to give you so many positives that you will bend and consider the line. To be honest I don't feel I can do that.
As a travel agent, if you came to me and asked the questions you have I would most likely try to stear you to another line.
Food choices do come with prices to pay, one being the pampering type of service you may be accustom to will not exist, but for many that is ok. Others it is not.
AS for the commercials, you know as well as most of us, ads are a marketing tool and no one really beleives you can wear snorkeling gear to dinner. I think anyone with an average brain would get the idea what is meant by the ads, or I certainly hope so.