15min from Nice there’s Monaco. So, the Casino question is answered: there’s no cooler Casino than Monaco. But there’s another one in Nice, near the end of the beach to the left, if you’re looking towards the sea.
For a good meal, there are several restaurants at Vieux Nice. I can’t recommend anyone in special because it’s been a while since I’m there, but I’m sure you’ll find one of your likes. Dancing is also at Vieux Nice, there are several “boites”. I hope you enjoy your time there :)