In my experience, there are DR testing strategies that are effective regardless of the industry you support. You need to determine the scope, objectives, and goals as with any test/exercise. You asked all the right questions that can be answered by the business and technology leaders with your guidance and recommendations.

I have led a variety of DR tests, some included the vendor that managed an environment or applications and others were driven internally. Wherever you land, the ultimate goal is to test application restoration times and validate restored applications are functional for business operations within the required timeframe (business RTO). At minimum, participants should include both technology and business recovery teams/owners.