The train ride doesn't necessarily have to be 4 hours. It's somewhere between 2 hrs 9 min. and 5 hrs 5 min. Check out http://www.b-rail.be/int/E/

Not since Hoverspeed discontinued the Ostend ferry route. The ferry terminal at Calais is really intended for people travelling by car or by organised coach tour, rather than by public transport (other than to destinations in France, at least). Anyone coming to Belgium by public transport would usually be on the Eurostar in which case you would get off at Lille and take a train from there either direct or via Kortrijk.

If you want to use buses, which in Europe are used either for short journeys in and around towns or (especially between countries) very long ones, you still have to start by taking the train from Calais to Dunkirk and from there (bus station outside railway station) bus 2B goes to Adinkerke and La Panne, at either of which you can switch to the coastal tram to Zeebrugge (www.dekusttram.be) and from there you can get a bus (791) to Brugge.

A lot of Brits go to Adinkerke to buy tobacco and I note that one of the tobacco shops runs a free minibus, take a look at www.day-tripper.net/tobaccoinbelgium.html. Obviously you would be expected to stock up on tobacco and would NOT be expected to be carrying a lot of luggage, but it might just be a possibility.