Hi Bruce,
If it was my trip, I would eliminate #2 because the first part of the trip has been on the water, so Lake Como - although a different look & vibe, would be too similar. And for Italy, I wouldn’t want to give so much time to Milan.
Your Option #1 gives you some excellent historic sites at both Normandy for WWII and the Loire Valley for French history. Those two areas feel different from each other, so that’s a nice itinerary. We flew from Seattle to Paris and immediately took the train to Caen, France near Bayeux. It was a long day, but I would suggest the same for you, if possible to give you your Paris time period at the end of your trip. No need to stay overnight at CDG; we always take the RER from the Luxembourg Garden neighborhood to the airport for our early flights.
Option #3 is nice, but I would redistribute some days and make one change. Those days in Nice will fly by - so much to do! I would give Nice four nights, and switch Avignon to Lyon. You could do Nice - 5 nights, Lyon - 2 nights and Paris - 5 nights (stay in Paris the last night). We have stayed several nights in Avignon. The Pont du Gard is very interesting, we also took a nice minivan tour of the Luberon villages, and Avignon was fine, but there’s so much more to do around Nice. Because the Italian/French border used to be west of Nice, you can enjoy the feel of Italy in the Italian section of Nice and also take the train over to Menton to explore the photogenic colorful Italian buildings & hilly lanes. The Villa Rothschild & gardens are exquisite, etc., etc. i was in Nice for five nights in 2019 and definitely want to go back to explore much more. I definitely recommend the Nice Food Tour! Excellent food and a few hours well spent!
We really enjoyed Lyon, and it’s a short train ride back to Paris. The Vieux Lyon neighborhood is wonderful to experience (we stayed there), and the Gallo-Roman museum is definitely worth seeing!