I've been to Calabria once with my mother for four weeks. There is the western coast which is tourist-y. And then there's the eastern coast, where we stayed. We were there around Ferragosto (August), and about the only tourists in the place. City of 5-10k people. All of the other people were just visiting their families and so on. Lots of robust southern Italien men with gold chains.. if you know what I mean. We actually had a fun time. In the beginning, the weather is nuts. You have like 40°C in summer and think you can't do anything. After a week or two you've accustomed to the climate and it's pretty great. It's about the brightest place I've ever been to (when we returned to Hamburg I though someone flipped the light switch off). People are friendly. Food is fine (such an awesome memory.. it was Ferragosto, so the local restaurant offered, like every restaurant in Italy does, a big menu with lots and lots of food. Anyways, after two hours or something we've finally finished (didn't finish each) all courses.. so, after desert, the group of "robust southern Italian men wearing gold chains (yeah, I mean this literally)" order a plate of pasta. I mean, they've eaten like 1kg of food, and now, after dessert, they order a freaking big plate of pasta!!!) Whatever, I think I'm not really helpful so far.
What I can tell you is this: not much tourists; not much to do (really, there just isn't much other than unfinished buildings, if that's your thing (could make great photographs there), then gerat); friendly people; decent food; good weather. However, I'd much rather prefer Donoùssa, a small island located in the Kykladen in Greece if I wanted a week or two of not doing much. We've been there twice a few years ago and it's been just lovely. A really really small island, very friendly people, like two restaurants and one supermarket. We both (literally) cried when we had to leave after four weeks... both t imes. This is where we stayed at: http://donoussa.heimat.eu/index.html
I guess she's still doing it, if you're interested I can e-mail her. Beautiful setting. However, I'm not sure when you're planning to get married.. now? December? Next July? You shouldn't visit these parts of Europe in winter. It gets really ugly.
But you seem to want to go on some sightseeing anyway, and that's definitely the wrong place (like I said, very small island).
So, yeah, I wouldn't choose Calabria. Much rather something in the central/northern Italy. More to visit. What about Tuscany, in the region around Firenze, Poppi and so on? Some great restaurants there too.
The pictures of Ljubljana look very promising. Never been in "Eastern Europe", so can't comment on that.