thinks she is on par with the boss before meeting him
Yes, that what she tells her husband at the end. That's she's not so capable as she thinks. However what is hard to believe for me is multiple times she's aware of the boss game, his personality. And even like this she falls again and again with the first night being absurd
Only because of sexual frustration which doesn't fit her personality overall.
Exactly. Ok, Hutch is not a master in bed, but she wasn't sexually unsatisfied whatsoever. So it's hard to follow the logic that she's completely on the hand of a guy whom she knows is a sociopath, only because he's good in bed. Even more the fact that she's emotionally vulnerable with him. With a young or/and naïve girl/woman, not the case until the night scene.
I'm not so sure that he is a wimp
He's depicted as one to the point of caricature after the garden scene. A guy with some personality will impose himself to leave the house after what he saw at the garden and confront her wife. Instead he doesn't open his mouth, knowing what's coming after. Even after the bathroom scene, he doesn't want to confront her wife.
It's like accepting he has lost in a battle and that's exactly what the boss suggests to him in the last conversation, to accept that
Yes, I can see that. But the wife is offering him a way out, even if they both know that he's not good in bed. He lost a battle and he's not even fighting for a new one. He just yields the initiative to his wife.
I just hope the husband won't end up like watching his wife fucking with another man.
The only condition he sets to his wife it's that he doesn't want to know what's happening during the "activity".
In Addison we hope

At current state, Hutch is walking zombie, only her can ignite a spark in him. I don't see any other possibility.
I agree. As other user said, she knows things because she's a family member and works also with him.
But she lost this game badly and she seals her faith as cum dump.
She lost with him during the first meeting. Then she's aware of the shark she's facing and wants to cut the ties. She has the skills to do it, instead she decides to become a slut. There is this breaching in her mindset that I'm not buying, only because the guy can fuck her good.
nor is he a wimp or loser
He's depicted as so beyond a pathetic level. He's incapable of cutting short a situation that he knows was out of wife's hands. He could have confronted her. Even at the end, when the wife suggests to move out and start over, he's not even fighting. He's just letting his wife doing what she wants.
Having said this. I totally agree with you, the writing is very good. Out of the norm regarding the level of most of the games in here.