Paris to Southern France Itinerary Feedback

Hello, we'll be visiting France mid-October and after reading several travel books/blogs, this is the loose itinerary I've come up with, but I'm hoping those of you with more experience can let me know if there's a better way before I add detail. My biggest concern is getting back to Paris from Nice. Is taking a flight, 6 hour train from Nice, or going back to Avignon for TGV train better? We'll be flying into CDG and we've been to Paris before:

Day 1 (Oct 13th) Arrive CDG at 3PM, Take 6PM or later TGV train to Avignon, sleep in Avignon

Day 2 (Oct 14th) Pick up car. Explore Arles, Pont du Gard, Les Baux, stay in area

Day 3 (Oct 15th) Continue to explore Provence, drive 3 hours to Nice

Day 4 (Oct 16th) Explore French Riviera

Day 5 (Oct 17th) Explore French Riviera

Day 6 (Oct 18th) Explore French Riviera

Day 7 (Oct 19th) Explore half day, then either return car to Avignon and take train, or fly back via Nice Airport.

Day 8-10 Explore/stay Paris, Take 2PM flight home on the 22nd

Open to any suggestions, especially about transport between the three main locations: Paris, Provence, Nice Thank you!