Any suggestions would be appreciated.
If IT systems manage anything quality related, they should be covered in your audit program. You got that partially correct in the event that it's not just business continuity but also disaster planning/recovery.
For Finance, it depends on what functions they perform. In most of the companies I have worked for, Procurement is part of Finance. Does finance play a part in approving suppliers? Do business contracts include quality language that should be in quality agreements or are they separate? What about sourcing new suppliers or materials. How do specifications get approved and communicated to purchasing? Who "owns" the ERP system? It's likely also finance, so what quality elements are there in the system and how are they controlled?
Just some suggestions.
I believe that is the end end result of a good audit process: improvement.
Regarding Finance, I would audit them from the perspective of context of the organization. They get the opportunity to see all the players from suppliers, customers and internal costs through cash flow. This is also potentially a good place to see cost of quality performance which can lead you down other paths during the audit.