Perhaps I'm misunderstanding your email, but if you cancel your Verizon contract, you'll lose all access to make calls/text/whatever on it. With a wireless contract, although they don't spell it out this way you're paying for 2 things, the phone service and the data plan, which covers things like text and using the web on the phone. You can circumvent the later as you are doing by connecting to home wifi when you're home. But if you cancel the Verizon contract, you won't be able to use the phone at all.

A better option might be to see if they have a cheaper plan than includes less data so you could keep using the phone as a phone.