Itinerary--Paris to Nice Help Needed

I'm not an expert, but Beaune is maybe 150 miles southwest of Paris, so you would be back-tracking, or at least triangulating, to go there after the Loire. And in my opinion, Beaune isn't all that interesting. It has the medieval hospital and the wine tasting cave, but I myself prefer to taste wine at the wineries and talk to the makers and see the landscape and vineyards.
After your time in the Loire Valley, have you thought about the Dordogne? It is scenic for photography, there is canoeing on the river (depending on the season, I assume), and the prehistoric art caves are really worth seeing. There are also some castle ruins that would be very photo-worthy.
And remember that France is about the size of Texas, so driving distances are more than you might think just looking at the map.
I'll be curious to see what other people suggest!

Suggest u opt for another chateaux in loire than chambord as it is huge and mostly empty.
Cheneceoux or other might be better but def see the outside from rd. Have your 21 yr old drive that would tire anyone easily. Yes if u are ok with dordogne the canoeing , pics, prehistoric caves and foie gras farms are a great visit. The villages are sm and distinct, again have your son drive. But it is istant from loire.
Provence is more convenient from loire though. Beaune is interesting but perhaps a little boring for your son. The surrounding vineyard countryside gorgeous but again more scenery. There are horse stablesnr beaune . Also have u considered guedeleon. A medieval castle reconstruction currently being built by orig methods. Could be fasinating for both of u. It is about hr from paris south.

16 days for ... Paris + Normandy + Loire Valley + Burgundy + Provence + Cote d'Azur.
I think you should be looking at less stops, not more, even with a 21 yo.
Perhaps drop Burgundy ??
4 nights in Paris, and 3 each in all the others.
A car would be helpful in Normandy and the Loire Valley, less so in the south where trains are useful.

another vote for Chenonceau

Aix-en-Provence is a university town with French and exchange students from all over the world living there. If he would like it, you could use it as a base to visit other sites.

Other than that, you should ask him what he'd like to see and do: prehistoric caves, Roman ruins (everywhere but particulary Vienne and south, not to miss the theater in Orange and the Pont du Gard), Renaissance chateaux (Loire Valley) but try to find medieval chateaux too, challenging walks and climbs (La Solutre in the Macon among many), inventions (DaVinci's house)? Have him read through some guide books, but there is much more to do than is listed in a general guidebook. Once you have an idea, you can go to the local websites for details on the areas. Following the RS tour may not hit his interests best.

FYI, the Loire--Tourraine area to be exact-- has very interesting troglodytes (many of which were inhabited until the beginning of the 20thC.) and a fascinating troglodyte castle (Breze) there. This is an example of how some of the most interesting sites may not have made it into a general guidebook, but are easily found on the local website. Finally, Chambord may be empty, but it has interesting architecture said to be designed by DaVinci--so again a reason to ask your son what's important--architectural design, interior decor, etc.

Thank you all! I will start researching the many suggestions. It sounds like in general backtracking and getting over to Beaune may not be worth it. Thanks again...I'll be in research mode for awhile. fyi, we are going late May 2016.

Arrive Paris (4 nts)
Pick up rental car in Rouen
Driving thru Normandy + Loire Valley (6 nts)
Return rental car in Orleans
Train (via Paris) to Provence + Cote d'Azur (6 nts)
Depart Nice