I'm not sure (can Netherlander Ehellions tell me?) but I think the Netherlands are one of those countries where you don't pick up food and eat it with your hands....sandwiches, hamburgers and so forth are eaten with a knife and fork. Of course, as PPs have said, they're so used to tourists that I'm sure no one would look askance at U.S. eating habits.
Also, marijuana tourism is on the way out----by the end of 2012, only residents with ID cards will be permitted to buy pot in the coffee shops. This is already the case in some cities, but I don't remember off the top of my head which ones.
Have a great time, TaurusGirl! Such a lovely place to visit.