The relative preference here is a function of the middle eastern law of hospitality. A host would even give his life to prevent harm to a guest. Scottish Highlanders had a similar law of hospitality (which is why the Glencoe Massacre was such a shocking crime to them.) This law seems to obtain wherever climate conditions are hostile and a traveler might die if not given hospitality.
Just so. The laws of hospitality are sacred in many societies.
That scene in Sodom when the father offers his virgin daughters to be raped rather than allow the rape of his male guest is horrifying, and I believe it is meant to be horrifying. What it says is that the crime proposed by the Sodomites would be so horrible that even the worst crime you can think of would be preferable. I would never take it to suggest that letting the daughters be violated would be a good thing to do.
The angel guest, of course, renders the terrible choice moot; the violators are suitably blinded by darkness and destroyed in the rain of fire.