You left Nassau, Bahamas off the list of ports for the NCL Epic.
I have to disagree that the NCL Epic has limited activities for children. The NCL Epic probably actually has more for your children's ages. They have bowling alleys, an Aqua Park with water slides, batting cage, rock climbing wall, repelling wall, Basketball/volleyball court, jogging track, Teen's Club, and Spider Web Climb. Your children may also enjoy on the Epic the entertainment of Blue Man Group (free), or the Circus dinner show (fee).