I too like you itinerary, and will be doing part of it in August (hopefully).

1. Try to get a diesel rental car. They perform very well, no untoward noise or fumes, and you'll save at least 25% over the cost of unleaded gasoline every ime you fill up;

2. Try to hit the (sp?) Viactualmarkt (food market) in the very center of Munich - all kinds of foods, great place for a casual lunch.

2. Try to route part of your Venice to Nice trip through Ravenna (great mosiacs), then via the A14 through Cesena (world-class ceramics museum), and Bologna - many North Americans skip this part of Italy when they do the "Triangle" and to me it's one of the most charming parts of Italy.

3. Outside of Nice, try to visit Juan les Pins, Antibes (pPicasso and a fort) and Grasse (perfume ingredientss).

4. be sure to walk the Old Town of Nice,and also don't be alarmed by the rock beaches in Nice - they're supposed to be that way!!

As far as security, like other posters have said, you don't have to be paranoid, just use good common sense, take basic precautions (for example, don't leave a coat in your back seat - the thieves may assume you have stuff underneath) and you'll be fine.

And don't forget the trip reports!