I work at AutoDesk and here is my unofficial opinion. Your data is secure. They take cloud security very seriously. They undergo standard, external audits to verify that security standards and processes - the same kind of standard audits that other vendors go through. Check the AutoDesk Trust Center for more information.

The points you make may be accurate but they have no bearing on the security of all our customer data stored with us. I take its confidentiality and security very seriously and I believe my co-workers do the same.