Then Jesus was being dishonest. His words there have to be taken literally. If Jesus talked about "ifs" that were not possible, then there could be no "ifs" and Jesus would then have been lying about a possibility that could never have existed.
So in order to believe your interpretation, I would have to believe that Jesus was a liar. Even if it were used illustratively, it had to be taken literally. If it were not a literally true statement, then it would have to be a factually false statement. You can't get around that.
Not so, Marlowe. Conditional statements ARE statements of fact. They show cause and effect. The conditional statement is valid. IF they had seen the miracles, THEN they would have repented. The fact that they did not see the miracles does not therefore invalidate the statement. However, the event has passed. They did not see them, and time would have to be altered for them to see them and repent. Therefore, it is not possible for them to do so.
Marlowe, if gravity suddenly ceased to exist yesterday then you would have flown right off this planet as it spun.
The fact that this has no real possibility of happening does not invalidate the factual conditional statement I just made, nor does it make me a liar for stating it (illustratively I might add). You can't get around that :)