It is possible that I don't understand all of your data sources, but as a side comment, special characters in a field name are often troublesome. Might not lead to monkey blood, but are a good source of headaches.
If your question is why that last INSERT query doesn't append anything, you need to recognize that the INSERT INTO is actually a layered query for which the layer isn't completely obvious. You can take out the entire INSERT INTO clause and start a query with the SELECT DISTINCT clause (and the same FROM clause) to see what would be selected (and thus what would be inserted). If you can get the SELECT to actually select something, you can then put the INSERT INTO clause back into the query ahead of the SELECT clause and it should work.