Will your king's location have anything to say on your relationship with your vassals? i.e. you spend too much time away from a part of your kingdom and the nobles there will start thinking to independently and get delusions of grandeur.
In early medieval Norway the Kind would travel through the different regions of his land to look up on his nobles and assert his authority over them. Will this kind of overseeing be in the game?
Also, can vassals who are ill-disposed towards you/your house go together (especially in times of succesion) and support a pretender or another claimant to the throne? If so, what can you do to get them in line? (Except rally the King's men, raid their lands and kill the upstarts...

)