It's been tough to always move and find a new job, friends etc I agree a support system is needed. This woman has already given two full years fully devoted to the institution without question. In five short days. Do people that are that busy honestly not have time to even think about their SO. Once you both die, you will not be married in the afterlife and she will get assigned to be the polygamous wife of someone else. I keep the positive thought that it will get better. I find that having zero expectations, single parenting and having my own life makes our marriage work well.
Mormonism is a religion that's as manipulative as it is comforting. He should tell her that he will never convert, and that if she will not be happy unless he does, the relationship should end. If you do believe it fully, are you not really going to want him to make the conversion ultimately.
I also think he is not used to anyone telling him "no" or going against his opinion. If you are only after non-serious dates and spend a great time, you should be fine with this set up. Disease and Condition Articles. If you are a believer and are willing to go, then well and good. It has worked and my children are very protective of their father.
What about the folks at church. Everyone has their own sins and impure thoughts they need to overcome. Honestly I'd let things keep going. They don't have control so they easily a Fall prey to other doctors and nurses etc. Ultimately there are no guarantees but I'd say it's worth a shot.