1) I fully agree that a surrogate-key implementation is the correct one; as the one posted by Andrews before. In fact my actual implementation of the entity model posted in the security 3.1 reference manual is this way.

2)As mentioned before this experiment was only a rhetorical development exercise for understanding better the details of the awesome tagx library coming with Roo and its flexibility.

3) As a Developer I can tell you that it is doable -however not practically or recommended- on taking care on the foreign key as well.

Thx
jD