I just read your initial post, and I believe that I can relate to what you envisage. My background is telecommunications billing. As you can imagine, when you have a database with millions of customers, and (what amounts to) data that will be used to bill them....it has to be right.
We often used a tool that we made, called a 'SanityChecker', and it was exactly like what you describe.....a set of SQL statements looking for dependencies or constraint violations, where those dependencies/constraints couldn't otherwise be checked by the RDBMS' we were using (ORACLE, Informix).
I worked on two such billing systems, and the 'tool' proved invaluable.
If I interpret you correctly, the what you are saying is that it would be good/great is an ORM tool could generate a script containing a set of 'SanityCheck' SQL statements.
Or alternatively, it would be great to have 'a file that could be consumed by a program ' (e.g. a DLL) that may be used to check data 'before' it hits the database.
I can't speak for nORMa. My company is building Richmond, a competitor...but i'd say that either tool could do the first, and we (my company) are definitely working on the second. It would be great if RDBMS tools also had ORM (instead or 'as well as' ER) as a diagramming tool also (from my perspective)...I think it'd be great if SQLServer had ORM as a documentation/schema development tool...then more semantically rich constraint checking can be performed 'before the data is stored in the database'.
Is that a fair interpretation of what you are looking for?
As for a 'SanityChecker' type SQL Script...there's nothing wrong with that. The first billing system that I worked with costs in the millions of dollars, and it comes with the SQL script as standard (i.e. it is well known that RDBMS' can't fulfill all the checking we want).
Anyway, I hope this is a welcome adjunct to your post. I find your thoughts most interesting and inspiring.