Sorry to hear that this issue is troubling you.
I always recommend generating all such libraries completely parametrically from scratch.
That would have meant, way back then before you created any CAD content at all, defining a programmatic way to generate that CAD content from a database of parametric definitions and lists of dimensions of all your library parts.
I have been recommending that approach (mostly in vain) for about four decades now.
The people who listened to it back then are very happy now that they did.
They are all too few.
Most people go and implement CAD content by hand, over and over again, every time the system changes.
Well, so be it then.
If the content is generated programmatically from a database of rules and dimensions, you can simply implement a new content generator for each system that you wish to populate. The database content driving it remains unchanged.
Back to your issue at hand:
If you have tested using families based on the imported CAD geometry in Revit without problems, then that is obviously a feasible option.
However, you really need to test that this really works under all circumstances.
For instance, if you are a chair manufacturer, try using your CAD-import-based family in a hospital or airport with thousands or tens of thousands of instances.
That may cause problems.
Furthermore, it might not be easy to equip the CAD-import-based parts with all the dimensions that drive their different sizes, aka family types aka symbols.
Here is a recommendation to think twice before importing CAD into RFA:
http://thebuildingcoder.typepad.com/blog/2016/09/avoid-cad-import-in-rfa-aag16-and-endtrip.html#2
On a completely different note, please be aware that this discussion forum is dedicated to programming Revit using the Revit API.
Therefore, you cannot really expect any good answers to a question such as yours relating to product usage and content creation here.
You should try one of the non-API Revit product support discussion forums instead for that:
http://forums.autodesk.com/t5/revit-api/this-forum-is-for-revit-api-programming-questions-not-for/td...
The people there are much better equipped to answer your question than us programming nerds.
I hope this clarifies.
Thank you for your understanding.
Good luck finding an efficient and viable solution for your task!
Best regards,
Jeremy