Heather,
The life you wish to have with this man simply will never be anything close to what you hope it would be. If he is currently married and then divorces he will be either disfellowshipped or heavily reproved (kind of a public shaming without the shunning). It's a gamble, you never know what is going to happen.
It's not just that he cheated on you, it is also the way that he did. Plus the fact that he has no job, a crimal record and now a hisotry of manipulative behavior.
You continue to turn to the future hoping the past will fade away. You reason that the JWs the main thing standing in the way. That is simply not true. The JWS are just one part of the problem (and possibly a small part). If this man is telling you your future relationship depends upon him being able to patch things up in the JW religion then I'm sorry girl but this relationship is just going to continue running in circles. He is using the JWs as a way to manipulate you and avoid commitment. At this point you seriously cannot trust anything this man says.
If he really wants to marry you, let him make the effort to do so. If you have to find all kinds of ways in order to 'reason' with him as to why the two of you need to be married you are headed for disaster. You may be able to convince him to marry you but even then his manipulative behavior will continue. Troubble is it's not something he has chosen to do. Sure he may say he want's to, but his actions show that he could care less.
At the very least just tell him what you want and what he must be doing in order for your relationship to work (job, divoce other wife, other). Then wait for him to make the move. Quit lowering yourself down to his level.