Tuscany (Florence, San Gimignano and the monestaries on Tuscany/Umbria border) is I think spectacular for photography as is Venice, Cinque Terre, and Lake Cuomo. These areas seem easier in the sense you just walk around and take wonderful photos without trying too hard to find the opportunities-- just so much beauty all around.
France South is nice (I am less familiar with Nice/Monaco), more familiar with Savoie/Rhone-Alpes/Provence/Pays Basque/Toulouse but I think Italy is easier in the sense that France seems more commercial/developed even compared to Italy North. There are still great opportunities of photography in France but I think you need to take the slow roads (not pay roads) or base yourself in a spot and look for the good shots in which case you hit Tao Te's dillemma of time slowing down and 3 weeks not enough to hit everything.
I would also say that many places France/Switzerland, etc have changed alot in the last 10 years, places that uesd to have artistic boutiques (like Carcassonne) seem to have largely given way to more shops selling the same cheap tourist trinkets (and wooden/plastic/metal swords in Carcassonne). Aix used to be a great place to base yourself in the south, but now it's been so built up that the town looks incredibly different and sadly the Vieulle Auberge (awesome restaurant) closed down. So make sure whatever you research is still accurate in the last year or 2. Older forums and books may mislead.
A good alternative to driving is to take trains (TGV, Eurostar) for longer distances and rent car only to make a smaller circuit where you need it (Florence/Tuscany, Provence, etc). It is feasible to drive from paris to the south in a day or along the southern coast in a day, but frankly this can be tiring and you waste more time driving.
For wine if you are trying to be careful with budget, it's a good idea to buy few wines in local enotecas in Italy or Nicolas in France and drink in the hotel. In each case, you can give your inputs on price and what wines you like, get very good suggestions and opening a bottle in the hotel let's you share with friends a better wine at a lower price than in the restaurants. If you don't have a cork screw, the hotel will usually oblige. I've actually gotten pretty good recommendatoins on restaurants as well from the guy in the Nicolas in the Marais District Paris near Hotel De Ville. I guess if they know wine they probably know restaurants too...
Yes, way off topic. sorry...