I'm LDS and I'll tell you one thing. My husband lays a hand on me in anger and he's gone. I'll forgive him once, it happens again, and we're done. The LDS church does NOT condone staying with abusive spouses.
That said, there is a lot of pressure to make one's marriage work, especially if it is a temple marriage. I know several people who have stayed married in spite of the bad times, but none of the problems involved abuse, either physical or sexual. Most managed to work through the problems and are now happily married. Others got out, and I can't blame them at all.
No, it certainly doesn't -- at least with physically abusive spouses. Psychological abuse still seems to get a pretty free ride. My boarder will probably be in therapy for the rest of her life, after growing up in an LDS home headed by a psychologically abusive father, and held together by a submissive mother who was sure God wanted her and her children to put up with his crap, because they'd been sealed in the temple and it was supposed to be for eternity, and if she left she'd end up shut out of the celestial kingdom, while her daughters (if they toed the line for the rest of their lives) would be there living in glory with their abusive father. And nobody from the Church was encouraging her to take her girls and get out of there. And sadly, my boarder -- for whom the legacy includes serious chronic physical illness, stemming from all the psychological stress -- still believes that her mother was doing what God wanted her to do, and was right not to leave.
But in the Hacking case (as in the case of my boarder's family), there's no evidence (at least so far) that Mark was physically abusive up until the time he apparently murdered Lori. From what we know, I surmise that she stuck around in spite of serious warning signs, due to cultural/social/religious pressure to "make the marriage work", in the absence of concrete physical abuse.