Nope! Celebrity is owned by Royal Caribbean cruise line. They brought Celebrity cruises in in 1997 for $1.3 billion. Norwegian Cruise Line is owned by Star Cruises which is the World's third largest...
No, you still have to purchase beverages while playing in the casino. They do have a player's card you can register while playing that might earn you free drinks if you play often enough.
Gill cruises is not a newer cruise line. They have been in operation for about fifty years. In those fifty years, they have been offering very good quality cruises.