I think all of these things are fair game, as long as all the parties are consensual, birth control and disease prevention are performed, and no trust is being broken, i.e. the man in the "wife of another man" does not care. If all of these people (and animals) are unattached, do 'em all, I say. Note that I may not necessarily do these things myself, but I don't consider myself the moral watchdog to prevent other people from doing them.
Some caveats:
There is a big difference between "prostituting our daughters" and the daughters prostituting themselves. I have no problem with the latter if it is their choice.
Regarding incest: in the modern era where birth control is available, what is the actual harm of incest, as opposed to the harm caused by the censure of society?
My guess is that primitive man, after millennia, got it through his thick skull that doing it with sis made bad babies. So the taboo was formed and later somebody created religion and proclaimed "god" said it was bad. But if there are no children, I don't see a difference between incest and sex with somebody unrelated.
I wrote a science fiction novel in the late eighties, and one of the characters was from a genetically enhanced species that had direct conscious control over pregnancy. She couldn't get pregnant unless she wanted to. Therefore no accidental pregnancies, and no incest taboo. The word didn't even exist in her society.