Itinerary advice 15 days

Are you planning to take the train from Salzburg to Venice and from Venice to back home?

Correct, we are planning on taking the train to Venice and fly out of Venice home

Some generally comments --
Day 2 - 1/2 day Versailles Basically it will take all day with travel time to and from plus walking to and from train station and then a 1/2 day in Versailles.

Day 3 - Normandy - save it for another trip. The D-Day beach are too far from Paris. The beaches themselves are spread over 50 miles from east to west and timing of transportation to and from is not the best.

Venice - while some are huge fans of Venice, four nights is a lot of time in Venice especially in July. I would add at least one day to Salzburg. Venice is not the best airport to fly home from.

In general you have a lot of travel. When we change locations we plan of losing at least a half day if not more just in the logistics of getting in and out of hotels, finding and waiting for trains, etc., etc. A big mistake a lot of people make, especially first time, is the travel distances and time needed for traveling.

How about changing your itinerary to go to Venice from Paris? Then on to Salzburg and ending up in Munich? Or Paris to Salzburg then Venice and Munich. Might be much easier to get direct flight to US from Munich than Venice. I have only flown into Venice, not out of. My understanding is that any direct flight from Venice to US is scheduled early AM. There are logistical issues in getting from Venice proper to Marco Polo. Not insurmountable, but may be much easier to do from Munich than Venice. You could also take a day from Venice to add to Munich to meet with family. Just a thought.

....My understanding is that any direct flight from Venice to US is scheduled early AM,,,,,

No, the problem is that there are NO direct flights from Venice. All are early morning flights, sometimes very early, to connecting airports for the direct flight back to the US.

Is there any way that you could re-arrange your schedule to give fewer days to Venice and one or two more days to Paris? The first day in Paris will probably be a wash-out, if you're coming from overseas.

I agree that Versailles will take at least 8 hours, transportation included.

If you're taking a guided tour of the D-Day Beaches, I'd suggest staying overnight - you will probably be exhausted after Versailles and the Beaches.

Versailles is a full day trip including transport to/from there and I would do this day 3, not the day after a long flight in case you are still suffering from jetlag. The Normandy beaches aren't practical for a day trip due to transport logistics.

I have been criticised on this forum recently for suggesting alternatives to the OP's itinerary, but I am going to do it again and suggest that you reconsider the Venice portion of your trip! It's a great place, but it's eye wateringly expensive and will be hot and busy when you are there, so there will be queues to get into everything. I found the food to be very disappointing. Your children are of the age that they won't fully appreciate the art etc and may get bored and as Venice won't change in the next decade (or ten), I would suggest leaving this until they are older. It sounds as though flights from Venice aren't ideal for you.

Dropping Venice would permit you to add two days to cover the Normandy beaches or to visit say Berlin or Amsterdam.

Thanks for all this advice! We had added Venice, but weren't committed. We may change plans and fly to Salzburg first and end in Munich for the flight home. Looking into options now.

I think your ideas are sound - Paris, Munich, Salzburg, Venice.
Perhaps better, though, to fly from Paris to Venice, then train to Salzburg, before flying out of Munich.

Day
1. Paris (5N)
6. Fly to Venice (3N)
9. Train to Salzburg (3N)
12. Train to Munich (3N)
14. Day to Neuschwanstein
15. Depart Munich

Drop Normandy and devote a full day for Versailles. Perhaps consider a 4 day Paris Museum Pass for Days #2 to #5.

Consider this train connection for Day#9...
ECB 86
Dep 13:50 VENEZIA S. LUCIA (Italy)
Arr 19:45 ROSENHEIM (Germany)
IC 1269
Dep 19:56 ROSENHEIM (Germany)
Arr 21:00 SALZBURG HBF (Austria)

I would day trip to Salzburg from Munich to prevent losing a half day by changing hotels.

Venice is unique enough to keep it in your trip.

I second djp_syd's plan.

I agree with the others in dropping Normandy for this trip unless your heart is set on it.

If you keep Normandy, you can add the castles of the Loire Valley and drop Salzburg.

Just some thoughts.

Ok, thanks for all the input! After consideration of meeting up with family in Germany, here is the new itinerary. Hopefully we are almost there. We'd like to see bigger cities as well as small towns. Dropped Italy.
Day 1 - arrive Paris
Day 2 - Paris
Day 3 - Versailles
Day 4 - Normandy
Day 5 - Paris (pick up daughter)
Day 6 - Paris
Day 7 - Paris
Day 8 - Travel to Rothenburg ob der Tauber (6-8 hours)
Day 9 - see Rothenburg
Day 10 - Travel Rothenburg to Salzburg (4-5 hours)
Day 11 - Salzburg
Day 12 - Salzburg and travel to Munich
Day 13 - Munich
Day 14 - Hohenschwangau and Neuschwanstein
Day 15 - Munich
Day 16 - fly home

Any way you could stop at Neuschwanstein on the way between Munich and Salzburg, rather than making it a long day trip? I hate backtracking.