Hi Mark,
An ODBC connection is fine as long as you only use it for read operations. Only write operations (including calling B1 system stored procedures that create transactions) through such a connection would be considered a violation of terms for support.
If read access is sufficient for your purposes, you should be aware that it would circumvent most if not all user authorizations functionality.
Depending on the requirements (I don't know about BI), you could consider an xml file and/or web service solution (using for example the DI server).
Regards,
Johan