If these are actually answered in Fifteen's run, just tell me that.

But, first, why wasn't Fifteen wearing trousers? He got a copy of the shirt and kept the tie, while not getting a copy of the vest, but if the shirt copied, why didn't the trousers? Or were the vest and trousers considered 'outerwear' by the process, with everything else considered 'under wear', and that's why the trousers didn't copy like the shirt did?

And what happens if Fourteen gets killed again? Does he just die, or does he still regenerate? If he DOES regenerate, does he become an exact replica of Fifteen, or does he become a brand new incarnation? If he does regenerate, does that mean Fifteen isn't actually Fifteen but a brand new One, starting a brand new line for this particular Timelord, more like a clone than a regeneration?

Like I said, if these are answered in Fifteen's run, just tell me that, otherwise go ahead and give me your theories!