The ability to reproduce has never been a factor of allowing marriage; otherwise, sterile individuals would not be allowed to marry. There is, in fact, considerable legal president for this in US Law.
Agreed. I was mentally including that in the "benefit for society" category.
Money would only be included if making money somehow benefited the society. On a more obvious level, spending time doing things like defending the "village" (culture, tribe, state, nation), farming/food gathering, shelter building/maintenance, infrastructure improvements, helping to raise existing children. Anything which help promote the survival of the society.