Provence itinerary guidance

Overall, I think you have your goals well aligned with days. Like, on the face of it there’s nothing I’d suggest changing. Only thing I’ll note is to let the good market days/towns guide some of this. Idk, maybe that’s how you have your day in Isle-sue-la-gorge planned. My only other note: I disliked Avignon and preferred Arles, but if you’re only there for a day you’ll enjoy it enough. I’ll let you decide after a few days in Provence if the Verdun Gorge is worth the effort.

We are torn on whether we should visit to Verdun Gorge or Parc national des Calanques.

Does anyone have one that they prefer over the other?

Verdon gorge is truly stunning, and is very close once you are in Valensole (where the lavender will be in bloom in late June), so it would be my pick. It will be a long day from Ménerbes, but you can reasonably combine a visit to the lavender fields with a drive along the northern shore of the Verdon Gorge all the way to Couloir Samson, where you can take a short hike into one of the narrowest sections, then back via the route des crêtes which has the most impressive views.
Even though you will pass through, you might not have time to visit Moustiers-Sainte-Marie in the same day. I do not think you would miss that much: while charming, I find it a little bit over-touristed and I prefer the Lubéron villages.

By the way, I'm assuming that your Isle sur la Sorgue day is a Sunday? That's when the big antiques market takes place together with the food market.

And why Maussane-Les-Alpilles? Once done with Les Baux, I would much rather head to Arles, stopping at the Acqueduc de Barbegal on the way (a max 30-min stroll along a ruined Roman acqueduct). A thorough visit of Arles would take a full day, but a half-day would already give you a very good overview of the city and its monuments.