Renting car for travel in Normandy and Loire Valley

Never heard of St-Pierre-de-la-Gare, but none of that will be too difficult. Do check out Europcar for renting in Caen. That company never charges for dropoffs at different locations within the same country. Not saying Hertz doesn't, I just know I've always been happy dealing with Europcar.

Ive rented in one France location and dropped in another with no problem. Europecar and Kemwel are what Ive used the two times Ive rented a car in France. Your plan is very common. Roads are fine. You can reserve all of this in advance ...

Um, it's St. Pierre des Corps. And the car rentals are right beside the station.

I believe Hertz has an office in both places, so yes, you can do that. Getting to the St. Pierre des Corps office is a bit tricky (some one way streets, but if you've got GPS or have looked at Google maps instructions, it's fine.
Renting a car is renting a car, so I'm not sure what your question is there. Make sure you have an IDP (International Driver Permit) before you leave home. Buy it at your nearest AAA office. Carry it with your DL.
France is a modern country. By and large it's road systems are good. Streets in small towns or the older areas of cities can be narrow. Spend some time learning the European road signs. And don't speed! At all! France uses traffic cams to nail speeders, and you don't want to end up receiving tickets in the mail months later (the rental company will supply your name and address to the police, and charge you for that service).
There are frequent direct TGV trains from St Pierre des Corps to Paris. You can either buy cheaper, nonrefundable tickets in advance from the SNCF website (if you know which train you want to take.) or just buy your tickets for the next train when you get there.

I think this is a smart plan. That way you avoid driving in Paris traffic. There are four rental agency offices across the street from the Caen train station--Hertz, Avis, Europcar, and Sixt. You might also look at the AutoEurope site to see if you can rent a car more cheaply through them. The roads are fine, though sometimes narrow compared to American roads, so I'd go for a small car. Bon voyage.

I've rented Hertz in Caen and other locations (CDG, Bayeux, Cherbourg) several times. It is very simple to book online. Just beware that Hertz moved their Caen office several years back. There are several rental car agencies right across the street from the Caen station. But Hertz is now about a block down the street. Take a right out of the station (West) and walk down to where the road goes under the railroad tracks. Cross under the tracks (right) and the Hertz office is just on the other side of the tracks on the left.

I find Hertz very easy to deal with—even if dropping off elsewhere. They won't ask for an IDL (if you want a lively debate, go to a recent thread on that subject). I just carry a simple translation of my U.S. driver's license, but Hertz isn't interested in that either. What they are adamant about is having the actual credit card with which you reserved your car with you at the time of pick-up.

It's never been an issue for me, but I would heed the advice about speeding due to many posts from people who learned after their return that they have been nabbed by photo speed machines on the highway. But overall I find France's speed limits (and roads) fine—and I'm known to drive very fast at home. Just keep an eye on the signs as they change, and your speed-o-meter.

Did essentially the same trip except rented from Enterprise in Caen and returned to CDG for our flight home (making a stop in Chartres) We rented from Hertz on a previous trip. Both companies were fine.

We used Europcar, picking up in Caen and returning in Nimes. But we drove from Normandy to Amboise and found the roads wonderful. We took the toll way most of the route and absolutely loved it -- great surface, very little traffic, beautiful landscapes (no advertising signs to spoil it), easy on/off to gas/food/bathroom stops. We were glad to have a car to visit various chateaux in the Amboise area. The only issue we had was we picked up the car on a Sunday, and the Europcar office was closed, but they left all the information and keys at a nearby hotel. Very slick -- except the hotel clerk didn't know where the car was. No problem, we just walked and explored more before locating the car.

We made this Normandy/Loire Valley trip 2 years ago and still consider it one of the best we ever made. We flew to Paris, rented our car at CDG and drove to Bayeux for the Normandy visits. We took the opportunity to see Mont St Michel, a bucket list item for us, while we were so close and had a car. We drove to Amboise, and like a previous writer in this thread, were so happy to have a car to visit the chateaus in the Loire Valley. This was the summer of the Seine flooding so the water closed Chambord and it was the only chateau we missed. You will be so glad you have a car in Amboise. It makes the exploring in the Loire Valley area so easy. The roads you use are beautiful and the scenery so enjoyable. A lot of the chateau roads were closed due to flooding but we had no problem finding a detour. If you do not have Villandry on your list then make a change and tour this incredible chateau.......mostly for the gorgeous grounds! We stayed at Le Manior Les Minimes in Amboise.....such a treat! Take advantage of the wonderful bakeries in Amboise for goodies to keep in your car as you tour! Amboise is charming.
We drove to Paris from Amboise and turned our car back in to Europcar at the Gare De Lyon train station.......what a zoo. We would probably still be there if I had not walked underground to find the garage where we were to turn in the car.......VERY DIFFICULT AND STRESSFUL! You are so smart to do what you are doing and avoid the car return in Paris!

Have a great trip......I know you will.

I've also returned a car to Gare de Lyon and I agree that it is incredibly stressful. There was NO SIGN on the parking garage for the rental company that was visible to a driver. I would have driven right past it, but I had looked in advance using Streetview on Google Maps, and that is the ONLY way I would have found it. Since there is another parking garage right next door--GPS or directions from a map app wouldn't have helped. So if you plan to drop a car off in the center of Paris, be very prepared ahead of time--or don't do it.