If you want suggestions on what an audit/repair tool should do, look in the dusty archives for documentation on the EDG tool from V4 to V7. This utility was very useful for analyzing and repairing corrupted files in a non-graphic environment. Here's an example of what it could do from the Bentley Wiki: https://communities.bentley.com/products/microstation/w/askinga/1064/verify-and-repair-files-with-edg
You can also look into what happens when an unopenable file is referenced into a new, clean file and copied in, to create a usable file out of corrupt data. I have saved countless corrupt files this way, but I'm not certain exactly how it works, internally. How can your audit/repair tool replicate that?
V8 shipped with the VerifyDGN tool, wich allowed to verify and repair errors. It did not allow any user configuration or interaction, just click and run. It got tanked with CE.
We used to use EDG back in the day and it was a great utility for error discover and resolution.
At the very least this new Audit / Repair tool should be able to zoom and highlight the discovered errors, or highlight the errors from a Fit View perspective and then offer fix options as to why the object is broken, let alone be able to fix the broken object.