I'll give it a go and maybe get the ball rolling.
Maybe one thing is that the role of RA may not be exactly the same throughout industry. What I would expect to be typical activities would include:
Managing submittals (so this pulls in doc control - both USING controlled documentation; e.g., references and control of their own docs; e.g., signatures, storage, etc.)
Managing regulatory aspects of complaints / adverse events (so there's probably SOPs for handling these matters)
So in terms of what would be assessed in an internal audit, you'd have to know what the responsibilities are and what (internal) procedures govern their activities.
Don't know if this helps but maybe it will at least spur discussion.