Hey sfkeller-
Yes, there is always room for discussion, we are presenting what our current thinking is.
RE: diagrams, I took the figures directly from Prof. Subieta's website and presentation material, so that's why they are like that.
However, I will also admit that I am a "black sheep" of sorts when it comes to this because I *detest* UML, I do not think it is a good choice at all for data modeling/schema description for any kind of database, object or relational. I don't like it for much else either, though I do use sequence diagrams and some other stuff once in a while to describe things.
-Mike