Don't want to ramble too much here, but one suggestion is not to miss Brugges in Belgium, one of my favorite European cities (towns). The highlight of many trips was bicycling north of Brugges along the canal to the Dutch border. And the town itself is wonderful. We stayed there and did day trips to Brussels, etc. Prague is magical, but you'll really want to stay right in the city -- walking around there at night is very special -- and do a marionette show -- perhaps a full opera production by "puppets" absolutely remarkable. Exact itinerary?? Can;t help you much, and we never do night trains, feel we miss too much. And for the sake of comfort, we have spent a full week in Amsterdam and traveled daily by train out to various villages, Delft, Hoorn, Harlem (spelled wrong, I know), Rotterdam, and the Hague. Distances are so short there, it's easier to stay in the city and go out by day. We also found Luxembourg fascinating for a couple of days (along your route), but not everyone does.