Sam2,
I believe that the reason these things are not enforced by B”D these days is more then simply that “these are not assumptions these days”. Nobody would advocate compelling a woman in the above mentioned ways to do ANYTHING in this context, even on obligations that are assumed. These days they advocate counseling and/or other ways of working out misunderstandings regarding assumptions as to how spouses are assumed to act or be obligated towards one another. This is a good thing, and it’s a change from what and how it is written in classical texts of Halacha such situations should be dealt with.