It is strange that you didn't get the company field. When I go and use the csv export I see all the fields, including company and "Created on". If there are any fields that you can't see, changing the export type to "import-compatible export" should fix your problem. Make sure that you are exporting from a view of the customers, and not some other view (ie. your in the products view).

You definitely shouldn't have to use PostgreSQL and do a bunch of joins to get your data. Try going to customers, selecting all and going to export again.