Their is plenty to do in Cincy! KI is good for the kids and the casinos will be fun for you. I don't have much input on which casino is better though...I don't gamble!
Night life would be either Main street district downtown(clubish) or Mt. Adams (bars to chill in) right next to downtown.
The Newport Aquariam is in Newport (on other side of river from cincy) which is always an attraction. There are a couple of nice places to eat over at Newport on the Levy also.
I would try to go see Chris Reindl at his place in Blue Ash! He is rigging the 28 Bat boat! He is only a couple of minutes off of 71.