My experience is that if a man is insecure and angry at the world, and taking it out on you in some, he will simply USE a religion to try and justify it, but that's probably not why he's insecure and angry.
Some people are attracted to JWs because they're depressed, controlling, or mad at the world and it seems to offer them a solution to that, but it doesn't change things too much and underneath it all, they're still angry and controlling sorts of people. Some learn a veneer of civility or piety that they slap over that, but it's not their true self. It may just be that he was always an angry and controlling person about some things.
One thing I don't know is if he was always like this or he just started being an occasional surly bastard to you since he left the JWs. If he was always like this anyway, except around other Witnesses when forced by social pressure to make nice nice, then he's got some serious personality problems.
If he's just been like this since he quit being a Witness, it could be a transition of sorts, where he's just mad at them and the world and taking it out on you because you're handy. Don't be so handy. Just leave the room or the house and say something like "When you decide not to treat me like crap, we can talk, but until then, don't talk to me like that, you're being an ass." If you can't assert yourself that way without feeling scared or insecure about consequences, you really do have a problem and he's genuinely abusive and you need to make a decision about how much of this you're willing to take.
My husband went through being a grumpy butt at times when we left off being Witnesses...he was pretty disillusioned and pissed off at them and the world and would occasionally get surly with me, nothing horrible, just "Leave me ALONE!" and go brood or play computer games for a few hours or go piddle in the garage alone, not wanting to talk right away.
"Shut up" is a bit rude, but sounds like he just can't take any more talking at the moment more than actually outright abusive (although he's being unpleasant, obviously). "Fuck off" is crossing a bit of a line for me, but it all sounds like ways to distance himself, in various degrees, and that's a more extreme way of distancing yourself.
I'd want to know why he's working so hard at distancing you at times. There has to be a reason. It may not have anything to do with the Witness thing, it could just be something to do with him.
One thing I try to remember that most men rarely want to talk out their problems like most women do, at least, not at first. They want to brood, then fix them in some way, but most men tend to think talking about a problem is fairly ineffective until they've sat and thought on it a while. The "shut up" and ignoring you at times could simply be that, he's wrestling with something big and isn't ready to talk about it yet or it could be that he's got too many "issues" to be successful at a relationship with ANYONE until he gets it all sorted out.