Travels in Provence

Just a couple thoughts come to mind...
It looks like you're getting off of the plane and going directly to Avignon via rail. Then renting a car and driving to Isle sur la Sorge immediately after? This is ambitious to say the least...jet lag is not to be underestimated even if you are able to sleep on your overnight flight. I would recommend waiting a day or two to travel to Avignon. Check into a hotel in Paris, let your body adjust, and then head south.
To me, your itinerary is OK - a bit rushed for my taste but you'll get a good overview of the area. I always err toward having more time rather than less and rarely do I spend less than two nights in any one place. Checking out of lodging, driving, and then checking in again always requires more time than you think it will, even if you have a car.

There's nothing wrong with arriving at CDG and immediately taking the train to Avignon, however I would spend the night in Avignon to decompress and pick up the rental car the next morning.

I agree with previous poster that for me it's too much moving around. When I went I rented the car in Avignon (after spending a night there) and drove to Roussillon, stopping to see the Pont du Gard on the way and then spent 5 nights there seeing all the same places as you plan (except for Ansouis) as day trips. I do like to settle in and come back to the same hotel each night to avoid all the packing and unpacking. Why not go from Avignon to Ansouis for 4/5 nights and day trip from there, then move to Vaison la Romaine for remaining nights.

While I agree that the first travel day is a pretty long and tiring day, I'Isle -sur-la-Sorgue is a very short and easy drive from Avignon. If I remember correctly, it's only about a 30 minute drive. I guess it all depends on how you (personally) typically feel after a long flight, but it's doable.

I was there in late May and didn't see the poppies, but by the beginning of June the lavender was starting to bloom.

Frankly you can often visit two or three villages in one day. Gordes for example can be seen in an hour or two. Same with Lourmarin and probably Ansouis. Are you planning on visiting markets? The Friday market in Lourmarin is terrific as is the Sunday market at Isle sir la Sorgue. I recommend visiting Domaine de Mourchon in Seguret during your time in Vaison.

The Senanque abbey is near Gordes. We were there around 18:00 so we could listen to the monks chanting at vespers. It was glorious listening to the sounds echo off the old stone walls. We attended the service, but I think you can also hear the music from outside the building if your schedule doesn't allow time to attend the service. The Abbey is in a beautiful setting in a valley. I think there is a well-marked walking trail that leads between Gordes and Senanque, which sounds appealing but which we didn't take.

I recommend a visit to Fontaine-de-Vaucluse, a small, charming village not very far from Gordes, Senanque, Lourmarin, etc. Along with some other attractions, it is home to the Musee d'Histoire 1939 - 1945, which presents the visitor a view of life under fascism and the fight against itl. Both sobering and inspiring. The museum is dedicated to the mayor of that period, whose support for the Resistance "earned him a one-way ticket to Buchenwald," as my Cadogan guide says.