This coupled with drinking at "UK speed" in a country where bars stay open until the landlord decides he's made enough for the night can make for an interesting evening/night/morning
Oh god don't get me started ! I used to live in Brussels - you could spot the Brits plastered down the street from about 50 yards. Double strength beer and unlimited opening time. One of the main Brit haunts, the Irish pub Celtica, was open pretty much all night and served Belgian brews by the pint - which would probably horrify the locals.
Brussels is kind of understated as captial cities go, Brugge is one place that lives up to the hype and definately worth a visit. I really enjoyed the coastal ride (see how our continetal cousins 'do seaside') but some say it's too built up and busy. It's not wilderness anyhow. Ardennes are very pretty. It depends how much time you have. I'm probably not much use at advice, I was both working and studying full time and didn't get to travel much.