Ninky -
Just to answer your points
"Well for a start, what happens to women who find themselves pregnant who don't happen to be divorced or widowed? No housing or benefits so - what? Workhouses?"
IMO there is no reason for anyone in the UK today to "find" themselves pregnant and be compelled to have the baby. If people are going to have a baby they should have the wherewithal to look after it.
"Plenty of people don't agree that 50 / 50 residency is in the best interests of the child. A child needs a home, a base, stability."
And conversely many people agree that fathers are discriminated against by the courts in family proceedings.
"As is says on the thread, who decides what an adulterous union is? Chap is violent, woman gets rid, meets nice man but can't start a new relationship until divorce as she'll lose her children."
Under current rules people find themselves having to compromise on relationships etc in order to maintain benefits or maintenance payments etc.
"Unmarried couples seen as inferior."
Well on that basis you must find all religions scary. Many many people believe that the best place to bring up children is in a stable married relationship.