I think on your second last point that is true, at least as far as sex and procreation is concerned, but in much less than 100 years.Does anyone else wonder where humanity will be sexually speaking, that is, in a hundred years. Today, homosexuality is generally accepted, they have rights etc. Yet a hundred years ago it was a huge taboo. Today, s*x with a 13 year old is "sick and twisted" behaviour yet a hundred years ago 13 year olds were getting married and procreating . Maybe in another 100 years they will be reversed again.... Or the puppy lovers will reign supreme.
My estimate would be about 10-20 years.
I doubt marriage will still exist, as we know it.
But some formality of relationship will survive, I'm sure.
Humans love to party!
Incidentally, I also believe within the next 30 years, AI, automation, and robotics, will wipe out money and (most) work.
In 70-100 years, all work.
Within the next 15-20 years we will see the first true androids.
Self drive vehicles are already with us.
And who knows where quantum computing will take us!
Makes you think, doesn't it?