I used to own a condo in North Beach, but didn’t spend much time there and eventually sold. South Beach is where the hip touristy area is. South Beach is indeed very crowded and parking and driving is bad in South Beach. North Beach is OK, though.
There is actually very good 24-hour bus service, but many people don’t consider buses to be “real” public transportation – only trains – and disparage it.
The one local eatery that is a secret that only the locals know about was called Chez Porky’s in Pompano Beach. It was an unassuming little place in a strip mall that was always packed at lunch and evenings. I was going to give you a link, but I looked for one and found much to my horror that it had been sold and the new owners didn’t run it well and it closed down.
But I see that someone else bought it and has reopened under the name Chez Ribs. It got a really good review from the Sun-Sentinal. Apparently the new owner was a real big fan of the original and has tried to recreate a lot of it. It is best-known for its assortment of exotic-flavored chicken wings and ribs, but it also serves a variety of cajun, Louisiana, and barbecue dishes as well as seafood. (Or at least the original used to.) The original owner-chef, Dario, was a Polish immigrant who was fascinated with American food. He studied American regional cooking and worked to recreate it in his restaurant. He did very well.
Alas, Dario is now a car salesman, I don’t know how the new owner is doing, but the reviewer likes him. If they still have it try the coconut soup (I hate coconut, but love this stuff), a wing assortment (try the raspberry), shrimp and scallops bayou or a fish dish, and the Kentucky Derby pie for desert.
If you’re not looking just for South Beach clubs and night life, try Zoo Miami (formerly known as MetroZoo) as the south end of Miami (not Miami Beach). They focus on the animals from hot climates (no penguins or polar bears) and have a great walk-through bird house where the birds fly free around you. And you can hand-feed giraffes (you have to pay for the food). Attend the various free shows and lectures – check the schedules.
If you can, fly into FLL, not MIA. Which one is cheaper varies a lot. But FLL is faster to get to and easier to get around and has free wifi.
Speaking of which, if you rent a car, watch for toll roads. Both of the expressways from MIA are now electronic tolling. (No tolls from FLL.) You have no option to stop and pay cash. The rental car companies have your car enrolled in electronic tolling and if you use it just once, they will charge you a daily fee for each day of your rental PLUS the cost of the tolls. If you anticipate using a toll road, go ro Publix and buy a SunPass sticker and register your car on the SunPass web site so that the rental company doesn’t get billed.