SJC-TPE and SJC-CDG were both part of the post 9/11 cutbacks.
There should be more than enough O&D traffic for SJC to support this service without feed from elsewhere. The Chinese population in the South Bay is so high that they have their own shopping centers. Some Silicon Valley schools have as much as 80% Chinese enrollment. I don't know what the mix is of this population between Taiwan, Hong Kong and mainland.
My company does a lot of business with Taiwan -- there's a lot more than just computers going on there and the SFO-TPE flights have heavy loads from what I hear from our employees and Taiwanese visitors -- Eva, China Airlines, Singapore and United all serve that route.
My hunch is that this may be a more lucrative route for AA than Tokyo is, but they must protect their SJC-NRT route authority or I believe they could lose it, and at the least they'd lose their NRT slots and good slots there are hard to come by.
As for the Maui stuff, well everybody out here is serving Maui. Aloha does it out of OAK with 737's!