Alloted Schedule & In-Europe Transportation

Right, you got a lot on your plate. First, a car in Amsterdam would be an absolute nightmare. Second, if you are going to spend 2 days in Amsterdam, why do you want to spend 2 days commuting from Brussels? Just book a room and save the time and money going there. Paris is just 3 hours 15 min from Amsterdam on the Thalys train. You could never drive it in that time and yes, there are huge "repatriation" charges for dropping a car in another country. Again, you can take the train from Paris to Munich in 6 to 7 hours. If you want to spend some time driving through Germany, at least take the train to say Karlsruhe, then rent the car there so you won't get hit with drop charges when you get to Munich. You can back track into Alsace and see a very nice castle at Haut Koenigsbourg outside of Selestat, but there will be castles all over the place.
In Rome, you can take some day trips to hill towns or the beach by train or bus from Rome.

Jeff, I'd have to spend some time working out details for your proposed Itinerary, but generally speaking, well planned rail trips will be the quickest and most efficient travel method. The fast trains (which travel at up to 300 kmH) are amazing! YES, if you rent a car in one country and drrop in another, there's usually a HUGE fee associated with that. You can research rail journeys for all of the places you'll be visiting by using the www.bahn.de/i/view/USA/en/index.shtml website. You can travel directly from Paris to Munich via train (travel time ~6H:10M, 1 change, reservations compulsory for one leg). If you want to see Castles, I'd recommend using Munich for a home base, rather than stopping for a night or two somewhere else. It's easy to get from there to Füssen (Neuschwanstein, Hohenschwangau) or to Salzburg. The specifics will depend on which Castles you want to see. As you're travelling in July, I'd suggest pre-booking accommodations once you get your Itinerary sorted. That's peak travel season, so lodgings may be difficult to find in some areas. Good luck with your planning!

Sam, 1) I guess I wasn't very clear on the Brussels day trip thing - we got the best air travel rates flying into Brussels and we were able to redeem rewards to get a Marriott there for 3 nights. My plan was to take 1 day trip west to Bruges, perhaps thru Ghent. Then, take a 2nd day trip up to Amsterdam. So, we'd be heading out to Paris from Brussels rather than Amsterdam. Is there a specific train I should look at for this leg? 2) I like your idea re: a train to Karlsruhe, then renting a car there. 3) Is is worth my while to try to find the "right" rail pass given my itinerary or should I just purchase point-to-point tickets for the 3 of us? Thanks for the response. Ken,
Thanks for the rail website info - I'll check it out. Also, I appreciate the heads-up on July lodging/peak travel season.

OK, your forgiven! Brussels to Paris is the Thalys. You can get 39 Euro fare on July 8 if you buy nonrefundable ticket at: http://en.voyages-sncf.com/en/train-ticket/result?hid=1657#journey_5 Same deal (and website) leaving Paris to Karlsruhe.
When using the french rail site, always use a country other than USA as country of ticket collection (France is best). Otherwise you will be redirected to Raileurope, and you do not want that. Higher prices and fewer options. The bargain fares disappear when when they sell out, so if you can commit, buy now. And let your credit card co know as well or they will block the transaction.

The first part of your trip would be best served traveling by train. Then if you need to go from Amsterdam to Paris, you might also do best to go by fast train. Despite AMS and CDG airports being so large, only KLM flies between Paris and Amsterdam. I was looking for one of the budget air carriers, but there are none. From Paris to Munich, you'd probably again have to go by train. Air France and Lufthansa flies between the cities. Without budget air carriers, you'll probably find the fares too expensive. Munich to Rome is also with Alitalia and Lufthansa. You'd miss some beautiful mountain scenery by flying, especially if the train was by day trip.
You're taking on quite an aggressive itinerary for the time you're going to be there. Your stays would best be done in the big cities taking day trips if you have time.

I think your schedule looks fine! Different folks have different temperaments for speed of travel and rate of change. This trip is aggressive, but if you all are up for it, I say go for it. As mentioned above, using the train is really the best way to get between all of these cities. It is much easier and often faster than a car. And you don't want to deal with a car in the cities. So not worth it. That said, sounds like you want to drive in Europe! Take the train as far as you want into Germany and then pick up a car for toodling around Bavaria. Easy and fun to drive there. Drop off car in Germany to avoid crazy drop off fees. Be sure to reserve the car in advance, and really shop around. The prices vary wildly and you can often find a good deal if you are persistent. We find that traveling by train is such a treat. Since several of your trips are rather long, they will give you time to relax, nap, read up in your guidebook, Facebook, journal, repack your messy bag, taste all the chocolates you bought in Brugge, whatever. I find the long train rides to be wonderful breaks during a trip. 5 nights each Paris and Rome sounds good. You can research day trip options ahead of time, then decide to do them or not once you get there. You can easily fill 5 days in each city, even at a hectic pace!