Some one needs to fix that, Barradin is the brother of the guy that Alderban overthrew, making Barradin the true hier to the throne, but Barradin felt that Alderban was going to be the better ruler and gave up his claim.
by how old rurik looks he might need viagra if he wants to keep yup ^_^... as for the cousin thing, it was not uncommon in royal families.... and people still do it to keep the bloodline.
If you look back on your own family three I'm sure you will find a pair of cousins or 2 that have married, it was very common back in the old day's (pre Victorian era)