Speaking as a former JW who was in the exact same position of your boyfriend there are only three words I can tell you; "run", "run", and "run". I would do everything possible to get away from this guy. If there is only one group of things that I could change that I have ever done is the way that I treated some really wonderful members of the opposite sex when I was younger. He'll be making you play the games that a JW plays like no birthdays, christmas, valentines day, or anything like that. You've already talked about how he's lied to you about how his parents are always having to use the phone. What else will lie to you about?
You may be able to help this guy see the truth about the cult that he's in buy I doubt it. Has he ever tried to talk to you about his religion and convince you that stuff you believe is wrong? He probally does like you and doesn't want to put up with all the hassling from his parents. What could he do to get them to quit? Well, they wouldn't bug him as much if you were a JW too. Not only that but when he goes to his meetings he hears all about how great it is when you bring new people into the cul...religion. Don't let him change you. You seem like a bright girl with a good future. Don't throw it away for a loser.
You may actually be able to help him but I doubt it. At least not for quite some time. Look, plain and simple, save yourself the time, trouble, and hassle. All you'll get out of it is pain, hurt, and frustration. Trust me, I was your boyfriend more than a couple years ago and that's all any of my really great girlfriends ever got. When it comes down to it, you are the most important person in your life. Don't let some schmuck slow you down and mess with your life. Before you worry about saving your boyfriend you need to save yourself.
I don't need to fight
To prove I'm right
I don't need to be forgiven.