Could this cause a power to have Holy Day (unitalicised) and Festival (italicised) at the same time?  Do two copies of Sign or Fire cause the cost to be paid twice?

They count as any other components, so “Festivals cannot also be Holy Days.” and “A Power may only contain one instance of each component.” still kick in,  making those particular Trickster usages illegal.

Thanks.  Also, I think that a global worship component is a good way to recognize Godhead.

because I think maybe each incarnation should be limited in the number of powers that can use this component.

If someone with a load of Godhead Powers has the Godhead taken away from them, though, those powers all stop working.

Other than that, though, it gives free G. Worship just like “leader” does.