Heero Yuy said:
The problem there is that making Vader the main adversary in SWR, they run the risk of making Vader look like a chump if he keeps losing to these guys. Original villains won't have the same sort of expectations that the fans would have for Vader.

Well said. Plus, even adult fans don't really want that either, do we? Maybe if the Inquisitor fails enough times he'll serve to heighten Vader's effectiveness via contrast. Though I'd expect that more from a comic than serious character, it's not something I wouldn't mind. I'd love to see the character punished for his failures, too -- here's hoping.