ahiddenbird

I agree that it's really better to try and go to fewer places. Honestly, it's way more fun and you get to truly absorb the places you visit, rather than just getting a quick, tantalizing overview.

The less time you spend in transit, moving around from place to place, the fewer opportunities there will be for something to go wrong in transit. It's much nicer to get completely lost in Venice than it is to get completely lost on the way to Venice, when you know you only have limited time there as it is. Do you know what I mean?

If it helps you to trim down and rearrange, I've been to Salzburg lots of times and though its a marvelous city, I've always done day trips there. Its very walkable, and honestly, you can get a lot of it in in one day.

I think you could add one of the nights you have slotted there to something else.

thursdaysd

I don't understand why you are doing this big circle. From what you say, you only really want to see Paris in France, and you certainly don't need a car there. Nor do you need a car for the Italy leg, as you recognize. You should fly into Paris, and either take the train (see seat61.com for all you need to know about European trains) or budget flights, to Austria, rent the car for Austria, and take the train to Italy.