That's a great run down. I'll give this a try sometime soon I think.
The only thing I'm not sure about with that is how could you do global
messages, form specific messages, and component specific messages.
That's probably not a very likely scenario so it's no big deal if I
can't have my cake and eat it too.
Much as we (the JSF 1.0 expert group) would have liked to address all the possible application framework sorts of issues like this, there just wasn't time to do all that and still get the 1.0 version out in any reasonable time frame. So, we chose to focus on the view tier only capabilities (for validation, that means primarily things like checking formats, not semantic meaning), but tried to provide enough pluggable extension points so that application frameworks could fill in the gaps.
Your use case is the sort of thing that makes sense to look at in a JSF 2.0 time frame ... although one could also argue that application level validation frameworks are not specific to JSF, and it might make more sense to focus a specific JSR on just those sorts of issues.
Craig