There are bits of this that are at odds with current value systems, but also bits that accord with them.

Offering them his own daughters as victims definitely does appal anyone today, and I guess comes from a strong culture of obligation to guests - before your self or your family. Lot did not know they were angels so did not know the alternative existed.

On the other hand they agree with us that gang rape is very wrong.

The pillar of salt thing and the destruction of the city are weird. On the other hand there are many modern examples of people wanting to destroy a place or a people they believe to be wicked.

The incest is presented as something they did, not as morally right.

I like your interpretation of getting Lot's side of the story, but not too literally as this was an oral tradition that was only written down much later.

There are many wildly different value systems in the world today. None that say gang rape is fine, but many will blame the victims.

It may be because in those days that daughters were seen as a means of forming ties with various mens' families through children.

Either way, there is a strange ending to this story which is that Lot's daughters got him drunk and seduced him.