I've lived in Miami for about three years and don't know of a big local (and paid) theatre scene. There are three road houses in the Southeastern FL metro area (one each in Miami, Fort Lauderdale and West Palm Beach), all are beautiful facilities and have some good shows, theatrical and otherwise, tour through. It's definitely been nice as five or six close friends from my past have toured through the area at one point or another. However, as a local SM I don't know how much work is actually down here.
The city itself is... interesting... A lot of good and a lot of bad, and definitely a good place to be when you're young. It's incredibly diverse, which is great, but a large portion of the ethnic groups tend to stay with their own. Excellent night life, and excellent weather come October - May. Cost of living is high - not quite as high as NYC, LA or Boston, however I'd put it approximately on par with Chicago and Vegas. Not sure if you will be around tonight at 9pm, but stop by the chat if you'd like to me to elaborate or if you have specific questions about Miami.