Multiple views is definatley the way to go.
I've done table updateable views, but only for updating a single table and having the child or parent info in the view for display purposes. I would never change a primary key in a view, indeed I'd never change a primary key at all once it has been created.
Sounds more like you need a paramerterized view that is requeried based on the parent tables primary key.
Sigfried Trent, aka FoxMan
(Working from his secret code cave, FoxMan battles the forces of darkness lead by the deranged and mysterious Bug Boy)