I believe I have read that in Belgium, one can buy a ticket to a destination and get off and on enroute. Is this also true in the Netherlands. I have also read that whereas tickets may be purchased with credit cards in Belgium, that is not the case in the Netherlands.
Dutch Rail (at both the ticket machines and windows) only accepts debit cards with a smart chips. US cards don't have this chip so we're out of luck:( I'm not sure how Belgian Rail handles this as I've only paid cash when using their trains.
Yes, you can get on and off provide you are traveling on regular NS trains, that you complete your travel in one day, and you follow a logical path.
Also, it will cost you an extra 50 euro cents per ticket to purchase them at the window. And be prepared for machines that only accept coins and not bills.