A completely different approach to using BB might be what I planned to do last fall before BB was released(but I skipped due to delay in release).
Background to this was that I just hate anything firewire after testing a couple of major brands.
General tip - check DPC latency and turn off possible WLAN adapters. Major generator of dropouts and cracks and pops.
Anyway...
BB has a ADAT output that among other things are meant to be used to daisy chain two BB units, but may be used to connect to computer if that is equipped with a ADAT interface of some kind.
So getting a clean ADAT interface to computer(like RME internal cards) could be one way to get around driver stuff with Mackie. From what I hears the Onyx preamps are excellent.