What should be on a DVT (Design Verification Test) checklist?
A DVT should cover everything you promise to your customer in the data sheet. Ideally, you also have made a spec long before you've written the data sheet, and the spec may even have more details than the data sheet because you don't want all the little things to be published.

When you do the DVT, you test each and every parameter you specified before or while you designed the gadget. It's as simple (and as much work) as this.