That route looks boring but good. That's what I would take to get from A to B. Terwilliger is definitely more fun, and aside from one notorious intersection (Jonathan did some posts bout this on bikeportland.org), it's pretty safe and calmer than Barbur. However, it does mean a fair amount more elevation change. I'd ride them both before making it official and see which she prefers.
Regarding your last question, I dunno. I don't head that far South too often, but perhaps others (K'Tesh?) have.