Hi Keysguy,
Welcome to the boards and the wonderful world of cheesemaking!
I love the Keys! I have a house in Fort Myers and have done the boat shuttle to the Keys a few time. Nice little area you live in!
1. I have a 600+ bottle walk in wine cellar. (I keep it between 57 and 60 degrees with a humidity of 60 to 65%. I have read that this should work for cheeses such as cheddar. (someone correct me if I have ms-read) My big question is "do I stand a chance of introducing unwanted thing into my wine cellar if I age cheese with the wine?" I have thousands of dollars of daily drinker and collector wine and do not want to take the chance of ruining them. You'll need some ripening boxes with covers to help raise the humidity if ageing with a natural rind.
A lot of people age their cheese in a wine storage area. The 57-60F temp range is not optimal for certain cheeses, it's a bit on the high end, but should do the job. The danger at that temperature is getting some bad molds, but some cheeses like Jarlsberg are meant to ripen at that temp though. If you vac seal or wax your cheeses, then you have nothing to worry about. The one thing I would recommend before you start is giving your wine cellar a good sanitizing scrub so you start on the right foot.
2. What are the best choices for someone making the jump to more involved cheese making.
Acquiring cheesemaking books and participating in these boards would be a good start. Anybody can follow a cheese recipe, but understanding what you are doing will help you become a better cheese maker.