What do you think of this itinerary?

I'd fly more and drive less. Probably I'd cover less ground.

I'd avoid 1-night stands connected by night trains like the plague.

On a 32-day trip, I'd definitely vary the pace more. A bunch of quick stops are fine for a few days, but I'd want some longer stays, including maybe a whole week with a car someplace wonderful.

I doubt I would find the premium charged for renting a car in Germany and dropping it in France to be worth it.

That said, I'm not you, have a blast.

I haven't been to most of the places on your list (just Germany and France), so my comments are only worth so much.

I generally don't like to cover this much ground because I don't like to spend so much time getting from place to place. But it might be fine for you. I think the pacing is pretty good.

My biggest suggestion is to forget Switzerland. From what I've read, April and May are not the ideal time to visit the Berner Oberland. Plus, two nights is not enough. If you hit a overcast day, it will be for naught. Take those two nights and add them somewhere towards the end, when you might get tired of moving around so much. Why not spend one night on Mont St. Michel and then three nights in Bayeux. The D-Day sites are pretty spread out, and with one day you will just be able to see a few highlights. Normandy is wonderful area and worth more time.

Hello Browaslawht. You travelled at Europe before. Therefore I guess you know what you are getting into, travelling to many destinations in this proposed trip. Going to many places, in seven countries, being at each destination a short time, can be satisfactory for some people. But I recommend : at each place where you have overnight accommodation, stay there a minimum of two nights. One of the reasons for that is : most people do not sleep well, their first night in a hotel (or B & B). I recommend : do not do any night trains in this trip. I recommend : when you depart from Germany and Austria, drop off the rental car in Germany. Fly from an airport in Germany to an airport in France. Delete Switzerland from this trip's itinerary. Ride in trains in France. I agree with what Carroll said : spend more time in Normandy. In addition to seeing a D-day beach, you could rent a car at Caen for two days, drive east to Pays d Auge area, see apple trees and Chateau and two small towns there (one or two day trips from Caen). Drop off the car at Caen. Train from Caen to Paris, one night at Paris for the purpose of preparing for your flight from the CDG airport. Are you willing to delete a visit to Chartres from this itinerary ?

In St. Petersburg, take a day to visit the Peterhof. We took a taxi there, to arrive first thing to watch the fountains when the pipes are opened. It's a show complete with music. We took the boat back, goes from the pier to the Hermitage.

It all depends upon your energy level. In my youth I handled similar itineraries with ease. Now I need more time in one place when touring. If you can handle it, go for it.