You can't remove data. You can't active a smartphone on VZW without a data plan. That's why I think data is under contract. It cannot be removed.
As well, I cannot change phones either. My contract states I'm not eligible for equipment for two years.
VZW won't allow me to trade my Bolt for a feature phone. Not only that, all their phones now require a data plan. Even feature phones. They can't say that I must spent 200 dollars on a dumb phone at retail through VZW in order to drop my data plan.
You cannot buy another phone at less than retail price from Verizon during the two year contract, but you certainly can get a phone via another method (ie buy used, buy from Verizon at full retail, etc, etc) and switch the service to that phone. I've done it multiple times. How do you think these guys that try out a phone every couple of months do it?
If you break or loose your smart phone and have a dumb phone laying around the house, you may absolutely switch the service to that dumb phone and drop the data plan until you get another smart phone. Call Verizon, they will confirm. (However, now that unlimited data is going away you would never want to do this in the future because you would permanently loose the unlimited plan - I'm just saying it has been possible and will continue to be possible to do this).