Can I force CSV imports into an approval workflow? I know there is a check box on the Import options, but a user could just override that right? how else can I get them into the workflow?

On your Workflow header, select Context = CSV Import? I've never tested this tbh, but I would try that first.

There is a system preference under csv options to turn it on by default, and then you remove the permission that allows users to uncheck the box.