I wish I could help, Index. I got an X-Arcade thinking it would work well with PS2 games like Medal of Honor, where you need the little thumbsticks. But really it's not practical, switching back and forth between modes.
The most sensible thing for me to do (since I have no idea how to hack the thumbsticks) was just to use the control panel joysticks for games like madden and racing and so forth, where I don't need the thumbsticks. For games that DO require the thumbsticks, like Medal of Honor, I just use my wireless controllers. It's kind of a drag, but really, games like Medal of Honor and other FPS games aren't designed around arcade-type controls, so it's just as well.