Advance congrats on your wedding! France is a fabulous place for a honeymoon (ours was in late Summer in Paris & the Champagne region), so you're starting things off well. If you're using Rick Steves' guidebooks, you'll also have an outstanding reference for lodging and sightseeing suggestions. Food in Paris is often pricey, so we've gotten many meals at "ethnic" middle-eastern places with good, inexpensive falafel, kebabs, etc. We endulge in Parisian bread and pastries, though. Markets are a great place to pick up picnic lunches, but if you're going in December, picnics may not be on your agenda.
December can be a great time to visit Europe. We were in Rome, Sicily, and the Sorrento-Naples areas in December 2012, and Christmastime added a new element to sights and events that aren't there at other times of the year. The summer hordes of tourists won't be there, so musuems and other attractions should be much less crowded. Hours of operation could be shorter in December, though, with places closing earlier than they do in summer, so schedule accordingly. Also, your plans are in northern Europe at a cooler time of year, and you could encounter rain/snow. We had frequent rain in Italy that December, and it was sometimes cool, but not outright cold. However, this past November in northern Spain had some actual cold, rainy days, so farther north, you may need to snuggle to stay warm ;-)
You mention only one day for Bruges/Ghent - are you kind of just passing thru on your way from Paris to Prague? I'd try to fit in at least 2 days and 1 night in Bruges, if possible, but that might take away from your other destinations . . . maybe one less day in Prague? Depending on what you plan to see/do, you might want to see if allowing any more Bruges time is possible. Belgium is one of the world's great bicycling centers, and not sure if you would consider renting & riding a bike, especially in December, but that could be an active portion of your trip, if applicable. Lately, our trips have generally been spending more time in a smaller area, rather than less time in lots of places. Your plans allow for at least a few days, each, in some great destinations, so except for the quickie day in Belgium, you're not considering just a hit-and-run schedule, and it seems reasonable & doable. How are you planning on traveling between destinations - quick, cheap flights, train, rental car? Your transportation modes & times can affect what you will have time for seeing and doing, and could also affect your energy level and how casual/comfortable you are on your honeymoon.
