Challenge: how to count NULLs for each column in every table in VLDB etc.

I need to create a report which shows:

• Count of rows in each table - this can be done using system views
• Latest insert / update for each table - this can be done using system views
• Date of insert of the oldest record currently held in each table
• Count / percentage of NULL values for each column in every table in the database

So far, the solutions thought of involve complex dynamic SQL which performs multiple scans of 100+ tables in a 3TB+ database.

Does anyone have any bright ideas for how to do this?

Thanks

Andrew