Ah yes.

Just re-read this thread to as per Reegar's request.

I would like to have seen how it would have played out but for me the Han/Leia romance trumping the possible Luke/Leia romance is pretty much implied by the events of ESB without the need of Luke being her brother.

I still remain unconvinced that the snapping of Luke under the stairs works without the sibling/Force running in the family line.

The only other thing like that I can think of is Vader threatening to do something to Leia I don't think he has been equipped to do for decades or maybe arranging for the Emperor to have a child with her.

Sick stuff (almost Game Of Thrones level sick) but the sort of thing that would make him go in a flying rage and almost kill his father. Remember this the film where Jabba does something to Leia that Threepio can't bare to watch. So the film has hidden levels of sickness already.

If he fails Leia is dead anyway so just threatening to kill her is not going to be enough to force that sort of snappage.