I was just there in November for four days. I agree on the drive down from Miami, did basically the same thing. it is a very nice drive. As for key West, I liked it a lot, but not sure how much more I could drink. Here is a good site for info:
http://www.pubclub.com/keywest/index.htm
For food, it is not too far from the main strip I would reccomend Finnegans Wake. They have some of the best wings I have ever had. I think it is more of a local hangout, but they still treat tourists nicely (I had a great time).
http://www.keywestirish.com/ is there web site...
Hope this info helped