Southern Italy in December

We are leaving for Rome in late November and will be in Italy for ~3 weeks. We want to head south to the Mezzogiorno to take advantage of what warmth and sunshine there is before the winter solstice. We prefer small towns relatively unscathed by 20th century development and would also like do as many outdoorsy things as possible. My questions are numerous: (1) How difficult will it be to get around via train or bus? I really don't like the idea of driving unless I absolutely have to. Is there a resource (Web site or book) that will help me figure out what trains and/or buses to take from where and when? (2) When I look at guidebooks, it seems half of the recommended accommodations are closed in the low season: Will it be difficult to find places to stay? I would like to stick to inexpensive (i.e. less than $100/night) places and am willing be too not picky in order to so. Any suggestions would be appreciated. Someone suggested campingwhich I might considerexcept schleping camping equipment 6,000 miles doesn't seem like a "viable option." Hostels freak me out so they're not an option. (3) We would like to go to at least one national park. Parco nazionale del Pollino looks interesting but, again, how to get there? Are there tour guides who would pick you up and take you there? (As there are in the Caribbean.) If so, any recommendations/suggestions? Would a different park be better? (4) I have not completely ruled out Sicily but I am thinking if I have to rule out one region, that would be the one. Still if I would get "more bang for the buck" there I would definitely re-consider it. I'm sure it's fabulous but I want us to not have too much of a whirlwind/rush-rush type of trip. Molte grazie.