BBM - I don't think we have any information that indicates that BM and SM created a fantasy image of their marriage for others. IMO they appeared very happy on social media. Could this have been a facade? Sure but we have no way of knowing. We cannot know what went on in that family and what the dynamics were for that family behind closed doors and what was hidden or not hidden. For sure for a husband to murder his wife something was off. But what kind of prelude existed to that murder and for how long - we don't know. Melinda has given some insight as have other family members. It seems it was a family where the husband made all the decisions and the wife fell into line along with the girls... until perhaps the dynamics changed and the wife wanted something different and/or the husband wanted something different. I really don't think that happens overnight. IMO There had to have been signs of marital conflict within that house. What was the timeline? As an aside, IMO to portray a fantasy image of marriage, to your children, effectively limits your child's knowledge of how successful relationships work.
We cannot know the internal dynamics and even a psychiatrist living in their actual house might have missed a lot, because people are on their good behavior around outsiders.
But, we have an apparently shared desire to be upwardly mobile.
Then, we have snippets of what others have said about Barry's controlling and cunning personality. Giving allowances for the fact that Suzanne is the victim, it still seems to me that everyone who knew her spoke of her kindness, gentleness and compassionate nature. That doesn't mean she was like that at home, of course, but it's all we have.
Barry and Suzanne decide to move far away from their original home, striking out on a new midlife adventure, having only traveled for resort vacations (apparently). Suzanne used to work, but it's not clear how she occupied herself right before the move, save that she was clearly a full time mother and wife. She had begun (on LinkedIn) to look at self-help books regarding mindfulness and how to manage life changes and stress. She was also listing herself as a "life coach." I think she felt they were improving their chances at a better marriage and less stressful life by moving (surely they attributed Barry's explosiveness at work to stress?)
But moving is very stressful, and leaving behind a support network is stressful. Barry had had a close relationship with the pastor/family at the church in Indiana (where he had apparently attended all his life). If Suzanne had ever had to reach out to a pastor, that pastor would have already known Barry since childhood, back home. In Salida, it must have felt very different and therefore, more stressful.
Then Suzanne's cancer came back. So the Morphews were very high on the stress calculation list (change in household size, moving cross country, financial difficulties, work difficulties, trouble with the law for Barry and cancer). If the stories about affairs are true (The Interview Room is the source for that), then yet another stressor, and perhaps the biggest one. We don't even know how much time they spent together once in Salida, as MG seems to indicate Barry worked 7 days a week and others have said he was "driven." It couldn't have been easy starting his business over again.
DV risk goes way up under circumstances like this (and so does the chance of the healthy partner having an affair - that's what the research shows, anyway, with the proviso that the research I know about is mostly from California, but we have similar data from other states). A couple of WSers have posted about situations they know of where this has occurred.
I'd have to check my sources again before saying more, but there's definitely more that indicates a web of highly emotionally charged transactions within the family in the year or two or three before Suzanne disappeared.