Hey get there early, a national game there is always stuff going on, back in the day I would always see the Bills play the fins on Monday Night. Pre game there would be a bonfire with an effigy of Kelly burning in it, always got the crowd going. As someone said it is like a carnival and such a good time.
As for restaurants, where are you staying. South Beach has some fun places for people watching on Ocean Drive, go late in the day to get end of beach and early dining, personally this brings back some good memories I would always go to the News Cafe, after clubbing between 4-5 am to get breakfast and a chocolate shake, not sure why but it always fit the spot. Not sure what clubs on Collins and Washington anymore, they seem to change names every few months.
http://upload.wikimedia.org/wikipedia/en/c/c6/Girls_dancing_in_South_Beach.JPG
Coconut Grove has a few restaurants, including the fore mentioned Marino's, haven't been there in awhile, but it was always busy, lotta hot chicas milling around. Though you are there with the GF and her fam, so be careful :)
Bayside is alright in the daytime, often have musicians playing and the Hooters has a good view.
Other than that I spent most of time between Kendall and Coral Gables and not much turista stuff.
If some of my stuff is dated I apologize, it has been awhile.