Remember when they first started - when she ran into him at the bar - he was a dick. He was drinking on the job and Tinder hopping and seemed bitter and troubled. He would have to be messed up to go for all the baggage you listed. Also, something I think that goes missing with observations of Helen as the woman scorned is she's quite bewitching to men and Vik got caught up in the Helen "thing." Her life sure is interesting, :) she's sophisticated and witty and he seemed to fall under the spell of some kind of twisted happily ever after with her. She uses sex to numb her pain just like everyone else on this show and she works it when she wants to.
I am one of the few people that like this season. OK wait I admit I shut it off and didn't return for two days when they started with the French prof POV, but I appreciate the nerve they had to do it! Early on in the series I was very distracted by the exaggerated reactions of people during their interactions but I would remind myself that it was one-sided perspective. The "training wheels" we had for viewing the last couple of seasons were the omniscient flash forwards (and video footage) that helped give us some of the "truth" along the way. We don't have that this season so the ride is causing some motion sickness (I'm also struggling with the prison guard story line), but I trust the writing and am interested in how this plays out. The acting is fantastic too. Maura Tierney is absolutely unleashed in this role.