Regarding what Hutch was doing when he went missing, there is some extra commented out dialog in the code.
It's good that it was removed because otherwise it would have limited the story going forward i think. at least now there is still a mystery on what he was doing. Plus i don't think it would fit with the direction it's going in. But hey, what do I know.
Regarding Hutch's being weak or mild, In the bathroom scene where Vivian gets angry and decides to leave, (side-note: Christian wouldn't let her leave, proving that all that bullshit about she is free to go, is just that... bullshit)
Hutch hears her plea....
He is getting ready to get up and come to her aid... Showing that he does at least have some backbone.
But ultimately he hears how she is enjoying it, and is a willing partner, further breaking his spirit. (Seriously Hutch my man, dump this bitch

)
And when he leaves the bathroom...
This is the face of a man who has been to war and seen things... this is the face of a man in shell-shock. A blank stare unable to feel joy or sadness, complete emptiness. I hoped this would be the face he always shows Vivian from now on, let it weigh on her.