Hello,
Today, there is no "easy" way to open native Inventor files from Vault into Inventor Read-only.
In Vault Workgroup, Professional, Office if you try to open an Inventor assembly containing Content Center Files into Inventor Read Only, you will obtain an incomplete result (missing content center files).
This is consider by Autodesk "as design". Then please vote to "finish the work" an make it really usable.
Thanks in advance.