Rail or the Road and what not to miss on the way.

Opening thoughts: The train system is handy and extensive but may require connections to get between two particular cites. Since you've chosen a compact area to explore, driving distances will not be strenuous. Driving in 4 countries and round-tripping back to Brussels (to avoid a 2nd-country car drop-off fee) sounds like no hardship, in this case.

As one who has lived in Europe and spent much of the year there, I would suggest going to www.eurail.com and getting a railpass then enjoying the ride. You can relax, let someone else do the driving and just soak up the sights. Choose central hotels in cities and avoid the driving and parking woes. I would definitely see Germany- great castles there-, the Netherlands, and Northern France as well. Belgium is tiny (as is Luxembourg) and Bruges needs no more than one day to see it all.

Before you commit to Eurailpass, figure the cost of point-to-point tickets. With the pass you still need to pay a reservation fee and the number of seats for pass holders may be limited.

In two weeks, I would choose two or three base cities and take a few daytrips. I would probably stick to Benelux and leave France and Germsny for future trips.

I have never rented a car in Belgium, but the train service is excellent.

RE: a railpass for Belgium...

Yes, if it's the one sold by Belgian rail that allows 10 domestic trips, particularly if two people are traveling together (everyone in your party can use it at the same time). You can simply buy it at the station. The cost is €70-some, last time I checked.

DO NOT buy a third-party rail pass for Belgium, it would be a complete and total waste of money. Ticket prices are relatively cheap, and because there are no advanced-purchase discounts, a rail pass offers no flexibility over simply showing up at the station and buying your tickets. But it costs significantly more.

The trains in Belgium are good between the major cities, less so between smaller communities. If you wanted to get out and explore the countryside, you would need a car, or be able to figure out the bus system (which is different between the two regions). Also, unlike much of Europe, Belgium has considerably less distinct villages and towns. It's more like heavily populated regions of the US, where towns sort of merge into each other. Driving is much like the rest of western Europe. Try to avoid rush hours around Brussels and Antwerpen, though.

Bruges has a few windmills, nearby Damme and Oostkerke too, crossing the Dutch/Belgian border there are several villages with also windmills. You can rent a bike or use public transport.

Have no idea if you have plans to stay in the Netherlands too, but to my opinion you can do a daytrip from Bruges to Kinderdijk near Rotterdam. You can drive to there via Antwerp to Dordrecht (direction Rotterdam). You can drive back through the Delta Region, visiting Zierikzee, (in between driving over the Storm Surge Barrier), Veere and Middelburg, all having windmills. However a stay closer to Kinderdijk will be more convenient, you can think about the old city centre of Dordrecht or tiny historical Willemstad. For this trip you definitely need a car.