Is it a fault being shy?

Shyness has its advantages and drawbacks like all things. I would assess it more on whether shyness is working well for you or not on those factors, than whether it's a fault.

That's going to encompass many subjective factors and is best assessed personally.

No, some people appreciate that quality in others. It's unfortunate that North American culture sees it as a defect.

No we are all different, shyness can be reduced greatly by gaining experience.

I wouldn't class it as a fault but it is a disadvantage.

No